From the second edition (1989):
rhetoric, n.1
(ˈrɛtərɪk) Forms: 4 [rethorice,] rettorike, 4–6 ret(h)orik(e, -yk(e, 5–7 rethorick (4 -ikke, 5 -ykk, -yque, retherique, 6 rethoric, -ique, -icke, rhet(h)orike, 7 rhet'rique, reth'rick), 6–7 rhetorique, -icke, rhethorick, -ique, 7–8 rhetorick, rhet'ric, 7– rhetoric. [a. OF. rethorique (mod.F. rhétorique), or ad. L. rhētorica, -icē (med.L. reth-), a. Gr. ῥητορική (sc. τέχνη), fem. of ῥητορικός rhetoric a.]

1. a. The art of using language so as to persuade or influence others; the body of rules to be observed by a speaker or writer in order that he may express himself with eloquence.
In the Middle Ages rhetoric was reckoned one of the seven ‘liberal arts’, being comprised, with grammar and logic, in the ‘trivium’.

13‥ Seuyn Sag. 186 (W.), Geometrie, and arsmetrike, Rettorike, and ek fisike. 1387 Trevisa Higden (Rolls) III. 361 Aristotle‥tauȝte eloquence‥as it is specialliche i-sene‥in his Dyalogus of Poetis and in Tretys of Rethorik. 14‥ Bewte will shewe 69 in Pol., Rel., & L. Poems, Was neuer clerk, by retoryk or science, Cowde all hyr verteus reherse to þis day. 1475 Bk. Noblesse (Roxb.) 25 The famous clerke of eloquence Tullius seithe in his booke of retherique [etc.]. 1481 Caxton Myrr. i. ix. 34 The therde of the vii sciences is called Rethoryque. 1553 T. Wilson Rhet. 1 Rhetorique is an art to set furthe by utteraunce of wordes matter at large. 1586 A. Day Eng. Secretary i. (1625) 10 Many excellent Figures and places of Rhetorique. 1656 Stanley Hist. Philos. v. (1687) 176/2 Rhetorick is conversant in singulars, not in universals. 1741 Watts Improv. Mind xx. §33 (1801) 193 Rhetoric in general is the art of persuading. 1836 Penny Cycl. V. 280/1 Having lectured successively in grammar, rhetoric,‥humanity, and moral philosophy. 1843 Mill Logic Introd. §3 The communication of those thoughts to others falls under the consideration of Rhetoric.

b. fig. or with personification.

[c1374 Chaucer Boeth. ii. pr. i. (1868) 30 And wiþ Rethorice com forþe musice a damoisel of oure house.] 1423 Jas. I Kingis Q. cxcvii, Gowere and chaucere, that on the steppis satt Of rethorike. c1430 Lydg. Min. Poems (Percy Soc.) 11 And Retoryk had eke in her presence Tulyus, callyd ‘Mirrour of Eloquence’. 1530 Lyndesay Test. Papyngo 11 For quhy the bell of Rethorick bene roung Be Chawceir, Goweir, and Lidgate laureate. 1642 Fuller Holy & Prof. St. ii. vii. 73 Some condemn Rhetorick as the mother of lies. 1742 Pope Dunc. iv. 24 There, stript, fair Rhet'ric languish'd on the ground.

c. A treatise on, or ‘body’ of, rhetoric.

1565 Cooper Thesaurus s.v. Rhetoricus, In primo Ciceronis rhetorico‥, in the firste booke of Ciceroes rhetorike. 1580 G. Harvey in Three Proper Lett. 32 To bring our Language into Arte, and to frame a Grammer or Rhetorike thereof. 1581 Lambarde Eiren. i. xi. 63 It is a good Counsell (which Aristotle giueth in his Rhetorikes ad Theodectem). 1654 T. Blount (title), The Academie of Eloquence, Containing a Compleat English Rhetorique. 1712 Addison Spect. No. 297 ⁋17 Aristotle himself has given it a place in his Rhetorick among the Beauties of that Art.

d. The top class or the second class (from the top) in certain English Roman Catholic schools and colleges. So †to make one's rhetoric.

1599 in Foley Rec. Eng. Prov. S.J. (1879) V. 569, I have made my rhetoric in these parts. c1620 in Mem. Stonyhurst Coll. (1881) 8 They go down two by two with their books under their arms, and first those in Rhetoric, into the Refectory. 1908 Stonyhurst Mag. in Tablet 25 Apr. 646/2 We are informed that any boy from Rhetoric down to Elements may join the class.

e. Literary prose composition, esp. as a school exercise.

1828 R. Whately Elements Rhetoric 4 Some writers have spoken of Rhetoric as the Art of Composition, universally; or, with the exclusion of Poetry alone, as embracing all Prose-composition. 1944 H. J. C. Grierson Rhetoric & Eng. Composition p. iii, Of University teaching in English I had enjoyed just fifty lectures at Aberdeen, of which twenty-five were devoted to Rhetoric or, as Rhetoric had come to mean under Dr. Alexander Bain and his successor William Minto, English Composition. 1953 T. S. Eliot Amer. Lit. & Amer. Lang. 5, I am happy to remember that in those days English composition was still called Rhetoric. 1972 Lebende Sprachen XVII. 35/2 US rhetoric—BE/US literary composition.

2.a. Elegance or eloquence of language; eloquent speech or writing. Obs. b. Speech or writing expressed in terms calculated to persuade; hence (often in depreciatory sense), language characterized by artificial or ostentatious expression.

c1386 Chaucer Clerk's Prol. 32 Fraunceys Petrak,‥whos Rethorik sweete Enlumyned al Ytaille of poetrie. 1426 Lydg. in Pol. Poems (Rolls) II. 133 Alle be that I in my translacioun‥Of rethoryk have no maner floure. 1562 Winȝet Cert. Tractates Wks. (S.T.S.) I. 25 As I persaue rethorik thairof verray small, swa I can espy na thing thairin abhorring fra the treuth. 1570 Dee Math. Pref. 46 Nor your faire pretense, by such rashe ragged Rhetorike, any whit, well graced. 1615 R. Brathwait Strappado (1878) 24 Heere is no substance, but a simple peece Of gaudy Rhetoricke. 1671 Milton P.R. iv. 4 And the perswasive Rhetoric That sleek't his tongue. 1733 Swift Lett. (1766) II. 189 The one word from you, is of much more weight than my rhetoric. 1784 Cowper Task iv. 491 Modern senators‥Whose oath is rhet'ric, and who swear for fame! 1825 Macaulay Ess., Milton, The sublime wisdom of the Areopagitica and the nervous rhetoric of the Iconoclast. 1837 Landor Pentameron 33 Escape from rhetoric by all manner of means. 1880 Swinburne Stud. Shaks. 269 The limp loquacity of long-winded rhetoric, so natural to men and soldiers in an hour of emergency.

c. pl. Elegant expressions; rhetorical flourishes. Also, rhetorical terms.

1426 Lydg. De Guil. Pilgr. 19774 That poete, Wyth al hys rethorykes swete. 1543 Bale Yet a Course 26 Neuer coude tolwyn throughlye knowe what these rhetoryckes ment, as are denuncyacyon, deteccyon, and presentacyon. 1589 Puttenham Eng. Poesie iii. ii. (Arb.) 151 Graue and wise counsellours‥do much mislike all scholasticall rhetoricks. 1628 Wither Brit. Rememb. 42b, Their fantastique Rhetoriques, Who trim their Poesies with schooleboy-tricks. 1942 W. Stevens Parts of World 143 Midsummer love and softest silences, Weather of night creatures, whistling all day, too, And echoing rhetorics more than our own. 1949 Koestler Promise & Fulfilment ii. v. 274 It was a disappointing speech—emotional rhetorics without a constructive programme. 1976 Sunday Times (Lagos) 3 Oct. 10/4 We cannot decide on the fundamental values and goals that will bind the present and future generations on the basis of vague ideas, irrelevant foreign slogans and rhetorics.

d. in ironical or jocular use.

1580 Spenser in Three Proper Lett. 14 Like a drunken man, or women (when their Alebench Rhetorick commes vpon them). 1595 W. S. Locrine iii. iii, I think you were brought up in the university of Bridewell, you have your rhetoric so ready at your tongue's end. 1613 Purchas Pilgrimage iii. xiv. (1614) 316 Some of them vpbraiding both him and other Christians with the names of dogs, Ethnickes, vnbeleeuers, and the like zealous Rhetorick. 1742 Fielding J. Andrews i. xviii, The rhetoric of John the hostler, with a new straw hat, and a pint of wine, made a second conquest over her. c1750 Shenstone Ruin'd Abbey 10 Fearless he of shouts Or taunts, the rhet'ric of the wat'ry crew. 1849 Macaulay Hist. Eng. iv. I. 450 He [Jeffreys] acquired a boundless command of the rhetoric in which the vulgar express hatred and contempt.

e. transf. and fig., said esp. †(a) of the expressive action of the body in speaking; (b) of the persuasiveness of looks or acts; (c) of artistic style or technique.

1569 Sanford tr. Agrippa's Van. Artes xxi, This daunsinge or Histrionical Rhetorike in the ende beganne to be lefte of all Oratours. 1587 Greene Euphues his Censure Wks. (Grosart) VI. 252 For he considered with himselfe,‥that liberality was the soundest rethoricke. 1588 Shakes. L.L.L. iv. iii. 60 The heauenly Rhetoricke of thine eye. 1597 Breton Wit's Trenchmour Wks. (Grosart) II. 15/1 Silence can best talke with wooden Rethoricke. 1644 J. B. (title), Chironomia: Or, The Art of Manuall Rhetorique. 1647 Cowley Mistr., Rich Rival ii, Whilst thy sole Rhetorick shall be Joynture, and Jewels, and Our Friends agree. 1669 Stillingfl. Six Serm. iii. 127 Every part of the Tragedy of his [the Son of God's] life, every wound at his death,‥were designed by him as the most prevailing Rhetorick, to perswade men to forsake their sins. 1712 Gay Trivia iii. 318 Mov'd by the Rhet'rick of a Silver Fee. 1851 Ruskin Stones Ven. I. i. 11 His larger sacred subjects are merely themes for the exhibition of pictorial rhetoric,—composition and colour. 1941 W. H. Auden in Southern Rev. VI. 729 Around them boomed the rhetoric of time. 1963 R. I. McDavid Mencken's Amer. Lang. 339 Among the neo-Aristotelian critics rhetoric is a current fashionable synonym for technique.‥ The Rhetoric of Fiction. 1964 J. Summerson Classical Lang. Archit. iv. 33 Well, there are three buildings which, I believe, demonstrate‥the ‘rhetoric’ of the Baroque. 1976 Howard Jrnl. XV. i. 52 The rhetoric of treatment will have to be replaced by the reality of treatment.

3. Skill in or faculty of using eloquent and persuasive language. Obs.

c1440 Partonope 5835 These lordis are chosyn be myn assent. The fyrst ys the kyng of affryke For his grete wytte and his retoryke. 1509 Barclay Shyp of Folys (1570) 17 Though he be wise and of might meruailous, Endued with Rhethorike and with eloquence. 1634 Milton Comus 790 Enjoy your deer Wit, and gay Rhetorick That hath so well been taught her dazling fence. 1680 H. More Apocal. Apoc. Pref. 7 The highest Encomium‥that the Wit and Rhetorick of men or Angels can invent. 1711 Addison Spect. No. 171 ⁋12 Joseph‥endeavoured, with all his Art and Rhetorick, to set out the Excess of Herod's Passion for her. 1750 Gray Long Story 117 But soon his rhetorick forsook him.

4. attrib. and Comb.

1656 Earl of Monmouth tr. Boccalini's Advts. from Parnass. ii. lxxxviii. (1674) 240 To Declaim‥publickly in the Rhetorick-School. 1806 H. K. White Let. to Bro. Neville 30 July, The Rhetoric Lecturer sent me one of my Latin Essays to copy for the purpose of inspection. 1884 Punch 23 Feb. 87 To unmask His rhetoric-shrouded weakness.