Of multiple origins. Partly a borrowing from Latin. Partly a borrowing from Greek.
Etymons:LatinIndo-; GreekἸνδο-.
< (i) post-classical LatinIndo-, combining form (in e.g. Indo-ScythicusIndo-Scythicadj.) of classical LatinIndus Indian (<Greek: see below),and (ii) Hellenistic GreekἸνδο-, combining form (in e.g…
< (i) post-classical LatinIndo-, combining form (in e.g. Indo-ScythicusIndo-Scythicadj.) of classical LatinIndus Indian (<Greek: see below),and (ii) Hellenistic GreekἸνδο-, combining form (in e.g. Ἰνδοσκυθία: see Indo-Scythiann.) of ancient GreekἸνδός Indian (see Indian.); compare ‑o‑connective.
Notes
Compare FrenchIndo-, GermanIndo- (formations in both of which are found from at least the 18th cent).
Formations within English are found from the early 17th cent. (earliest in Indo-Scythiann.), becoming more common from the early 19th cent.
In use with reference to the Indo-European language family as a whole (see sense 2) short for Indo-Europeanadj.1
Meaning & use
1.
Forming adjectives and nouns with the sense ‘Indian ——; Indian and ——’. Also: (in later use esp. in political contexts) combined with adjectives (and occasionally nouns) relating to the names of countries, nations, etc., with the senses ‘between the Indians and ——’, ‘jointly Indian and ——’, ‘of mixed Indian and —— descent, nature, or characteristics’.
Typically referring to India or to South Asia more generally (cf. Indian subcontinentn.), but sometimes (as in quot. 1891) referring to Indigenous peoples of North, Central, and South America (cf. Indianadj. A.2, Indiann. B.I.2a). The latter usage, while still current, is now increasingly likely to be avoided in favour of other terms: see discussion at Indiann. B.I.2a.
Frequently in geological, ecological, and ethnological contexts.
1826
At the Calcutta grammar-school..are two exhibitions expressly supported by some wealthy and benevolent individuals of the mixed or Indo-Briton stock.
R. Heber, Letter 18 February in A. Heber, Life of Reginald Heber (1830) vol. II. xxvii. 384
1857
This year I commenced at Jáfirábád, under the hospitable roof of the Indo-Abyssinian Governor of the place, Sídí Mohamed.
E. B. Eastwick, Autobiogr. Lutfullah xii. 353
1861
He indicates an original source purely Greek,..another Indo-Egyptian.
J. G. Sheppard, Fall of Rome xii. 675
1884
In Europe, before the introduction of the algorithm or full Indo-Arabic system with the zero.
Encyclopædia Britannicavol. XVII. 627/1
1891
In Paraguay [etc.]..the mass of the population is Indo-Spanish.
Times 8 January 9/2
1902
We talk glibly of Indo-European, Indo-Chinese, Indo-Malayan, Indo-Arabian, and Indo-Oriental Floras.
J. D. Hooker, Letter 2 March in L. Huxley, Life & Letters Hooker (1918) vol. II. 390
1954
Indian words in English: a study in Indo-British cultural and linguistic relations.
G. S. Rao(title)
2021
A man of some refinement, who came to us from Lucknow—a city that is a metonym for high Indo-Islamic culture.
New York Times (National edition) 16 May (T Style Magazine) 73
2.
Linguistics. Forming adjectives and nouns referring to (proposed) language families which include the family of languages to which Sanskrit, Hindi, Bengali, etc., belong (cf. Indo-Aryanadj. & n., Indicadj.1). Occasionally also: forming adjectives and nouns referring to (proposed) language families including the Indo-European languages (see Indo-Europeanadj.1 B.2a).
In such words, Indo- sometimes expresses the southern or eastern limit of the language family's geographical range in pre-modern times, the second element (e.g. Celtic, Germanic) expressing the northern or western limit.
1850
A more extensive examination of the Indo-Teutonic languages.
H. L. Mansel in North Brit. Review November 26/2
1884
The great group of nations which has been variously called Aryan, Indo-European, Indo-Germanic, Indo-Celtic, and Japhetic.
J. Rhŷs, Celtic Britain 1
1938
The primeval ways of the ‘Indo-Teutonic North’.
Burlington Magazine November 231/1
2001
Some linguists believe that these two language stocks developed from a common mother language spoken deep in the Palaeolithic (this is called the Indo-Uralic hypothesis).
With combining forms and related words, forming nouns and adjectives adverbs to which Indo- is in objective relation, as in Indologyn., Indophilen. & adj., etc.
Pronunciation
Stress is usually determined by a subsequent element and vowels may be reduced accordingly.