From the second edition (1989):
accent, n.
(ˈæksənt) [a. Fr. accent, OFr. acent:—L. accent-um f. ad to + cantus singing, a literal rendering of Gr. προσῳδία, f. πρός to + ᾠδή song, lit. ‘song added to’ sc. speech: see note under sense 1.]

1. A prominence given to one syllable in a word, or in a phrase, over the adjacent syllables, independently of the mode in which this prominence is produced.
Accent in Gr. (προσῳδία) is explained by Dion. Hal. περὶ συνθέσεως ὀνοµάτων ch. xi. as a distinct difference of musical pitch in pronouncing the syllables of a word, those having the grave or heavy accent (βαρεῖα gravis) being spoken at a comparatively low pitch, those having the acute or sharp accent (ὀξεῖα acūtus) being spoken as nearly as possible a musical Fifth higher (διὰ πέντε), and those having the circumflex accent (περισπωµένη circumflexus) beginning in the high pitch and descending a Fifth during the pronunciation of the same syllable. The same three varieties occurred in Latin, but their positions in a word followed very different laws. This variety of pitch disappeared for both Latin and Greek towards the end of the Third Century a.d. when the feeling of quantity was lost, and the high pitch in Greek and Latin became merely greater force, and this stress accent has remained the substitute for musical accent in modern Greek, in Italian and Spanish, and is also found in German and English. In Swedish and Norwegian a musical syllabic accent remains in use; in Danish it is replaced in some circumstances by a peculiar catch, and in others by stress, as in English. In French, where probably stress was at one time strongly marked, the difference for at least three centuries has been so slight that writers have disputed as to its nature and the position of the stress syllable. In all languages having the stress, a variable alteration of pitch and quality of tone always prevails, and is used to express varieties of feeling. This expression belongs to rhetoric. The grammatical varieties of accent in English are great, but are all varieties of stress. The position is fixed in words of more than one syllable. Monosyllables have various degrees of stress according to circumstances. Hence the distinction of syllabic accent for the first, and verbal accent, phr. accent, or emphasis for the second. (A. J. Ellis.)

1581 Sidney Def. Poesie (1622) 529 Though we doe not obserue quantitie, yet we obserue the accent very precisely. 1589 Puttenham Eng. Poesie (1811) ii. vi. 65 To that which was highest lift vp and most eleuate or shrillest in the eare, they gaue the name of the sharpe accent, to the lowest and most base because it seemed to fall downe rather than to rise vp, they gaue the name of the heauy accent, and that other which seemed in part to lift vp and in part to fall downe, they called the circumflex, or compast accent: and if new termes were not odious, we might very properly call him the (windabout) for so is the Greek word. a1637 B. Jonson Eng. Gramm. (1696) All our vowels are sounded doubtfully. In quantity (which is time) long or short. Or, in accent (which is tune) sharp or flat. 1748 J. Mason Elocution 26 When we distinguish any particular syllable in a word with a strong Voice, it is called Accent; and when we thus distinguish any particular Word in a Sentence it is called Emphasis. 1871 Earle Philol. Eng. Tongue xii. 525 Accent is the elevation of the voice which distinguishes one part of a word from another.

2. a. The marks by which the nature and position of the spoken accent were indicated in a word.
The old Latin forms (´) acūtus, (ˋ) gravis, (ˆ) circumflexus, are retained, but each one now represents mere stress, except in works on elocution where (´) now generally represents a rising (not a fixed high) pitch; (ˋ) a falling pitch (the ancient circumflex), and (ˆ) a rising followed by a falling pitch, not used in ancient Latin and Greek. Some writers use (ˆ) for length only, the same as (ˉ). The old meanings are quite lost. (A. J. E.)

b. Marks used to distinguish the different qualities of sound indicated by a letter, called diacritical accents.
The old ´ ˋ ˆ are mostly used, as French e é è ê in je, été, tiède, même, but a great variety of other signs have also been introduced. These diacritical accents sometimes distinguish meaning only, as French a à, la là. These marks are not used in English orthography. But sometimes ˋ is used to shew that -ed is to be pronounced as a distinct syllable, as learnèd, hallowèd, and some write é for a final e pronounced, as Hallé (properly German Halle). (A. J. E.)

1596 Spenser State of Irel. 30 Being likewise distinguished with pricke and accent, as theirs aunciently. 1611 Florio, Accento: an accent or point ouer anie letter to giue it a due sound. 1611 Cotgr., Accent aigu: a sharp accent marked thus ´, and much used. Accentuer: to marke, note, or pronounce, with an Accent. c1620 Hume Orthogr. Brit. Tongue (1865) 22 The grave accent is never noated, but onelie understood in al syllabes quherin the acute and circumflex is not. 1807 Robinson Archæol. Græca v. xiii. 470 The ancient Greeks used no accents, which are supposed to have been invented and introduced about two hundred years before Jesus Christ. After the Greek language became the favourite study of foreigners, it was necessary to facilitate the pronunciation of it by applying marks of accent for that purpose: and this, very probably, induced Aristophanes of Byzantium to invent and introduce those accentual virgulae.

c. Marks of various kinds placed over and under the consonants in Hebrew, serving as signs of tone and of interpunctuation; hence fig. the minutest particular (of the Mosaic law).

1610 Holland Camden's Brit. i. 443 That we, who sift every pricke and accent of the law, may see the upright simplicity of that age. 1659 B. Walton Considerator Considered 264 The Masorites‥invented the names and figures of the vowels and accents, which they have left to posterity; though the later Grammarians herein differ from the ancienter about the names, nature, number, and use.

3. The mode of utterance peculiar to an individual, locality, or nation, as ‘he has a slight accent, a strong provincial accent, an indisputably Irish, Scotch, American, French or German accent.’ Without defining word: of a regional English accent.
This utterance consists mainly in a prevailing quality of tone, or in a peculiar alteration of pitch, but may include mispronunciation of vowels or consonants, misplacing of stress, and misinflection of a sentence. The locality of a speaker is generally clearly marked by this kind of accent. (A. J. E.)

1600 Shakes. A.Y.L. iii. ii. 359 Your accent is something finer, then you could purchase in so remoued a dwelling. 1602 Daniel Musoph. st. cli. Our accent's equal to the best. c1620 Hume Orthogr. Brit. Tongue (1865) 27 We fynd the south and north to differ more in accent then symbol. 1711 Addison Spect. No. 29 ⁋4 The Tone, or (as the French call it) the Accent of every Nation in their ordinary Speech is altogether different from that of every other People‥By the Tone or Accent I do not mean the Pronunciation of each particular Word, but the Sound of the whole Sentence. 1772 Johnson in Boswell Life II. 14 I have been correcting several Scotch accents in my friend Boswell. 1789 T. Jefferson Wks. 1859 II. 559 He spoke French without the least foreign accent. 1840 Carlyle Heroes (1858) 247 Accent is a kind of chanting; all men have accent of their own,—though they only notice that of others. 1860 Hawthorne Marble Faun (1868) I. xii. 128 There is Anglo-Saxon blood in her veins‥and a right English accent on her tongue. 1930 H. G. Wells Autocr. Mr. Parham ii. i. 74 Underbred contradictory people with accents and most preposterous views. 1934 —— Exp. Autobiogr. II. viii. 522 He spoke with an accent. 1956 D. Abercrombie Prob. & Princ. iv. 42 Accent‥is a word which, in its popular use, carries a stigma: speaking without an accent is considered preferable to speaking with an accent.‥ The popular, pejorative, use of the word begs an important question by its assumption that an accent is something which is added to, or in some other way distorts, an accepted norm. 1962 Guardian 5 Oct. 9/2 They were poor, they had ‘accents’, the children went to State schools.

4. The way in which anything is said; pronunciation, utterance, tone, voice; sound, modulation or modification of the voice expressing feeling.

1538 Bp. Bonner in Foxe A. & M. (Catley) V. 155 He said with a sharp accent. 1604 Shakes. Oth. i. i. 75 Rod. Ile call aloud. Iago. Doe, with like timerous accent, and dire yell. 1644 Milton Education Wks. 1738, 138 And solemnly pronounced with right accent & grace. 1699 Dryden Tales from Chaucer, Good Parson 16 Mild was his accent, and his action free. With eloquence innate his tongue was arm'd. 1725 Pope Odyssey x. 402 Transform'd to beasts, with accents not their own. 1727 Swift Poisoning of Curll Wks. 1755 III. i. 151 What this poor unfortunate man spoke, was so indistinct, and in such broken accents. 1768 Sterne Sent. Journ. (1778) I. 123 I thought by the accent, it had been an apostrophe to his child. 1820 W. Irving Sketch Book I. 43 The accents of those we love soften the harshest tidings. 1831 Scott Abbot ii. 20 Echoing the question with a strong accent of displeasure and surprise. 1847 Hamilton Rewards & Punishm. (1853) iii. 120 The very accents of consultation are heard.

5. poet. A significant tone or sound; a word; in pl. speech, language; including both the tones and their meaning.

1595 Shakes. John v. vi. 95 Pardon me, That any accent breaking from thy tongue, Should scape‥mine eare. 1601 —— Jul. C. iii. i. 113 How many Ages hence Shall this our lofty Scene be acted ouer, In State[s] vnborne, and Accents yet vnknowne? 1663 Butler Hudibras i. iii. 186 Forcing the Vallies to repeat The Accents of his sad regret. 1718 Pope Iliad iii. 285 The copious accents fall, with easy art. 1777 Sir W. Jones An Ode of Petrarch 66 Soft-breathing gales, my dying accents hear. 1817 Byron Manfred iii. iv. (1868) 312 In thy gasping throat The accents rattle. 1857 Emerson Poems 16 One accent of the Holy Ghost The heedless world hath never lost.

6. Prosody. The stress laid at more or less fixed intervals on certain syllables of a verse, the succession of which constitutes the rhythm or measure of the verse.
English verse is theoretically marked by a periodical recurrence of strong syllables, having a loud stress, a certain number of times in a line, separated by one or two weak or unaccented syllables. The habits of poets do not however carry out this theoretical law. Thus in ‘to err is human, to forgive divine,’ theory would require to to be strong; similarly in ‘for the poor craven bridegroom said never a word,’ theory would require the first syllable in craven to be weak and both groom and said to be as weak as the -ver and a which follow. They are not so. Hence has arisen the conception of rhythmically or metrically accented and unaccented syllables, as distinguished from the grammatically or verbally accented syllables. Thus, in the above examples, to has the rhythmical and not the verbal or phrase accent, and craven has the syllabic but not the rhythmical accent; err has both verbal and rhythmical accent, divine has both syllabic and rhythmical accent. (A. J. E.)

1588 Shakes. L.L.L. iv. ii. 124 You finde not the apostraphas, and so misse the accent. 1589 Puttenham Eng. Poesie (1811) ii. iii. 59 Your ordinarie rimers vse very much their measures in the odde as nine and eleuen, and the sharpe accent vpon the last sillable, which therefore makes him go ill fauouredly. 1871 Abbott & Seeley Eng. Lessons for Eng. People 152 Accent in Metre if it fall on any syllable in a word, must fall on the principal Word-accent. Accent in Metre may fall on syllables that have not a distinct word-accent. We can never have three consecutive clearly pronounced syllables without a Metrical Accent.

7. Music. Anciently: the marks placed over words to shew the various notes or turns or phrases to which they were to be sung, these generated the neumes and the latter the notes. In modern music: stress recurring at intervals of time which are generally fixed, but may be varied by syncopation and cross accentuation.

1609 J. Dowland Ornithop. Microl. 69 Accent (as it belonged to Church-men) is a melody, pronouncing regularly the syllables of any words, according as the naturall accent of them requires. 1795 Mason Ch. Music i. 11 In respect to Accent, Rhythm and Cadence, Music becomes an object of criticism which supersedes what is purely harmonical. 1809 J. W. Callcott Mus. Gram. 41 The bars of music are not only useful for dividing the Movement into equal Measures, but also for shewing the Notes upon which the Accent is to be laid.‥ In the course of this work the accented will be termed the strong parts, and the unaccented the weak parts of a measure. 1867 Macfarren Harmony i. 4 The sense comprising rhythm, accent, and numberless delicate gradations.

8. fig. Distinctive stress, force, sharpness, or intensity; a distinction, or distinguishing mark, character or tone. Now esp. with on: emphasis.

1639 Fuller Holy War (1840) v. xxi. 278 Now these are the several accents of honour in the German Service. 1647 Ward Simple Cobler (1843) 37 The accent of the blow shall fall there. 1655 W. Gurnall Christian in Arm. i. 27 That which gave accent to Abraham's Faith, was that he was ‘fully perswaded, that what God had promised, he was able to perform.’ 1662 Fuller Worthies ii. 108 Marsh made amends for all these failings with his final constancy, being both burnt and scalded to death (having a barrel of pitch placed over his head, an accent of cruelty peculiar to him alone). 1863 A. Gilchrist Life of W. Blake I. 41 The interior, with its galleries‥and elaborately decorated apsidal dwarf-chancel, has an imposing effect and a strongly marked characteristic accent (of its day) already historical and interesting. 1947 F. Meynell in E. Barker Char. England xviii. 389 The design of the components—the type, paper, and binding—will show local accents. Since the difference between good and bad design‥may be a question of millimetres in the thickness of a part of a letter‥even these slight national accents are of great importance to the bibliophile. 1955 Financ. Times 5 Nov. 4/3 The accent in exports is likely to shift away from ready-made products to the sulphonates which are necessary for their manufacture. 1958 Times 15 July 7/7 Inside the accent is on comfort, with deeply upholstered seats which reduce fatigue to the minimum on long journeys. 1959 Observer 29 Mar. 12/8 The accent was on poverty, squalor and ugliness, but the balance was kept with comments on the good old days which never were.

9. a. Art. A touch of colour or light which serves to bring the features of a structure into relief or furnishes a contrast in a scheme of colour.

1849 Ruskin Sev. Lamps iii. 79 The Greek workman cared for shadow only as a dark field wherefrom his light figure or design might be intelligibly detached: his attention was concentrated on the one aim at readableness, and clearness of accent. 1888 Contemp. Rev. May 712 A few stronger touches, and an accent of light on the neck. 1900 Westm. Gaz. 17 Mar. 3/2 A trained eye which discerned at a glance where the accents of a building lay.

b. Something that emphasizes or highlights (esp. by contrast) a decorative style. Freq. attrib. Chiefly U.S.

1972 Times 15 Dec. 27/3 Lighting in general is indirect, with much use of spots, floods and accent lights. 1974 State (Columbia, S. Carolina) 15 Feb. 6-a/2 A beautiful Mediterranean credenza cabinet with double speakers, a perfect accent to any room decor. 1977 New Yorker 12 Sept. 87/2 It [sc. a purse] will fit in beautifully with its superb leather, accent stripe and stitching. 1984 Tampa (Florida) Tribune 28 Mar. 3b/3 (Advt.), Drexel, wicker accent chair in rich tobacco finish.

10. attrib., as accent-shift, accent-shifting.

1935 D. L. Sayers Gaudy Night xviii. 382 How dared he pick up her word ‘sleep’ and use it four times in as many lines, and each time in a different foot, as though juggling with the accent-shift were child's play? 1940 Amer. Speech XV. 200/2 Experimental study of the origin of secondary intonation (accent) in the Slavic languages. Accent shift has been accompanied by the introduction of rising inflection. 1926 Fowler Mod. Eng. Usage 386/2 Words in which accent-shifting is tentative only:—construeʹ v. (doubtful), coʹnstrue n.