late Old English (replacing Old English fers, an early West Germanic borrowing directly from Latin), "line or section of a psalm or canticle," later "line of poetry" (late 14c.), from Anglo-French and Old French vers "line of verse; rhyme, song," from Latin versus "a line, row, line of verse, line of writing," from PIE root *wer- (2) "to turn, bend." The metaphor is of plowing, of "turning" from one line to another (vertere = "to turn") as a plowman does.
The English New Testament first was divided fully into verses in the Geneva version (1550s). Meaning "metrical composition" is recorded from c. 1300; as the non-repeating part of a modern song (between repetitions of the chorus) by 1918.
The Negroes say that in form their old songs usually consist in what they call "Chorus and Verses." The "chorus," a melodic refrain sung by all, opens the song; then follows a verse sung as a solo, in free recitative; the chorus is repeated; then another verse; chorus again;—and so on until the chorus, sung for the last time, ends the song. [Natalie Curtis-Burlin, "Negro Folk-Songs," 1918]
some printed Latin text (usually Psalms li.1) "set by the ordinary of a prison before a malefactor claiming benefit of clergy, in order to test his ability to read. If the ordinary or his deputy said legit ut clericus (he reads like a clerk or scholar), the malefactor was burned in the hand and set free, thus saving his neck" [Century Dictionary]. See neck (n.) + verse (n.).
1869; Englishing of vers libre.
But it is possible that excessive devotion to rhyme has thickened the modern ear. The rejection of rhyme is not a leap at facility; on the contrary, it imposes a much severer strain upon the language. When the comforting echo of rhyme is removed, success or failure in the choice of words, in the sentence structure, in the order, is at once more apparent. Rhyme removed, the poet is at once held up to the standards of prose. Rhyme removed, much ethereal music leaps up from the word, music which has hitherto chirped unnoticed in the expanse of prose. [T.S. Eliot, "Reflections on Vers libre," New Statesman, 3 March 1917]
1560s, in drama, "person who speaks the prologue and explains or comments on events on stage," from Latin chorus "a dance in a circle, the persons singing and dancing, the chorus of a tragedy," from Greek khoros "round dance; dancing-place; band of dancers; company of persons in a play, under a leader, who take part in dialogue with the actors and sing their sentiments at intervals."
The Greek word is of uncertain origin, because the original sense is unknown. Perhaps it is from PIE root *gher- (1) "to grasp, enclose," if the original sense of the Greek word is "enclosed dancing floor," or *gher- (2) "to like, want," if the original notion is "to rejoice."
Extension from dance to voice is because Attic drama arose from tales inserted in the intervals of the dance. In Attic tragedy, the khoros (of 12 or 15 (tragic) or 24 (comedic) persons) gave expression, between the acts, to the moral and religious sentiments evoked by the actions of the play. English 16c. theater adopted a stripped-down version of this.
When a Poet wished to bring out a piece, he asked a Chorus from the Archon, and the expenses, being great, were defrayed by some rich citizen (the khoregos): it was furnished by the Tribe and trained originally by the Poet himself [Liddell & Scott]
The meaning "an organized company of singers" is from 1650s. Meaning "the refrain of a song" (which the audience joins in singing) is from 1590s; that of "a song to be sung by a (large) chorus" is from 1744. Meaning "main part of a modern popular song" (as distinguished from the verse, q.v.) is by 1926, originally in jazz. As a verb, 1703, from the noun. Chorus girl "young woman who sings and dances in a stage chorus" is by 1852.
Proto-Indo-European root forming words meaning "to turn, bend."
It forms all or part of: adverse; anniversary; avert; awry; controversy; converge; converse (adj.) "exact opposite;" convert; diverge; divert; evert; extroversion; extrovert; gaiter; introrse; introvert; invert; inward; malversation; obverse; peevish; pervert; prose; raphe; reverberate; revert; rhabdomancy; rhapsody; rhombus; ribald; sinistrorse; stalwart; subvert; tergiversate; transverse; universe; verbena; verge (v.1) "tend, incline;" vermeil; vermicelli; vermicular; vermiform; vermin; versatile; verse (n.) "poetry;" version; verst; versus; vertebra; vertex; vertigo; vervain; vortex; -ward; warp; weird; worm; worry; worth (adj.) "significant, valuable, of value;" worth (v.) "to come to be;" wrangle; wrap; wrath; wreath; wrench; wrest; wrestle; wriggle; wring; wrinkle; wrist; writhe; wrong; wroth; wry.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit vartate "turns round, rolls;" Avestan varet- "to turn;" Hittite hurki- "wheel;" Greek rhatane "stirrer, ladle;" Latin vertere (frequentative versare) "to turn, turn back, be turned; convert, transform, translate; be changed," versus "turned toward or against;" Old Church Slavonic vrŭteti "to turn, roll," Russian vreteno "spindle, distaff;" Lithuanian verčiu, versti "to turn;" German werden, Old English weorðan "to become;" Old English -weard "toward," originally "turned toward," weorthan "to befall," wyrd "fate, destiny," literally "what befalls one;" Welsh gwerthyd "spindle, distaff;" Old Irish frith "against."
"practiced, conversant, acquainted," c. 1600, from past participle of obsolete verse "to turn over" (a book, subject, etc.) in study or investigation, from French verser "to turn, revolve" as in meditation (12c.), from Latin versare "be employed, busy oneself," literally "to turn to, turn often; think over," frequentative of vertere "to turn" (from PIE root *wer- (2) "to turn, bend").