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.
Old English standan "occupy a place; stand firm; congeal; stay, continue, abide; be valid, be, exist, take place; oppose, resist attack; stand up, be on one's feet; consist, amount to" (class VI strong verb; past tense stod, past participle standen), from Proto-Germanic *standanan (source also of Old Norse standa, Old Saxon and Gothic standan, Old High German stantan, parallel with simpler forms, such as Swedish stå, Dutch staan, German stehen [see discussion in OED]), from *stathula, from PIE root *sta- "to stand, make or be firm."
Sense of "to exist, be present" is attested from c. 1300. Meaning "encounter without flinching" is from 1590s; weaker sense of "put up with" is from 1620s. Meaning "to submit" (to chances, etc.) is from c. 1700. Meaning "to pay for as a treat" is from 1821. Meaning "become a candidate for office" is from 1550s. Nautical sense of "hold a course at sea" is from 1620s. Meaning "to be so high when standing" is from 1831.
Stand back "keep (one's) distance" is from c. 1400. Phrase stand pat is from poker (1882), earlier simply stand (1824 in other card games). To stand down is from 1680s, originally of witnesses in court; in the military sense of "come off duty" it is first recorded 1916. To let (something) stand is from c. 1200. To stand for is c. 1300 as "count for;" early 14c. as "be considered in lieu of;" late 14c. as "represent by way of sign;" sense of "tolerate" first recorded 1620s. Phrase stands to reason (1620) is from earlier stands (is constant) with reason.
Middle English risen, from Old English risan "to rise from sleep, get out of bed; stand up, rise to one's feet; get up from table; rise together; be fit, be proper" (typically gerisan, arisan; a class I strong verb; past tense ras, past participle risen), from Proto-Germanic *us-rīsanan "to go up" (source also of Old Norse risa, Old Saxon risan, Old Frisian risa, "to rise; arise, happen," Gothic urreisan "to rise," Old High German risan "to rise, flow," German reisen "to travel," originally "to rise for a journey"). OED writes, "No related terms have been traced outside of Teutonic"; Boutkan suggests an origin in a lost European substrate language.
From late 12c. as "to rise from the dead," also "rebel, revolt, stand up in opposition." It is attested from c. 1200 in the senses of "move from a lower to a higher position, move upward; increase in number or amount; rise in fortune, prosper; become prominent;" also, of heavenly bodies, "appear above the horizon." To rise and shine "get up, get out of bed" is by 1916 (earlier it was a religious expression). Of seas, rivers, etc., "increase in height," c. 1300.
The meaning "come into existence, originate; result (from)" is by mid-13c. From early 14c. as "occur, happen, come to pass; take place." From 1540s of sound, "ascend in pitch." Also from 1540s of dough. It seems not to have been used of heat or temperature in Middle English; that sense may have developed from the use of the verb in reference to the behavior of fluid in a thermometer or barometer (1650s). Related to raise (v.). Related: Rose; risen.
Middle English seien, from Old English secgan "to utter, inform, speak, tell, relate," from Proto-Germanic *sagjanan "to say" (source also of Old Saxon seggian, Old Norse segja, Danish sige, Old Frisian sedsa, Middle Dutch segghen, Dutch zeggen, Old High German sagen, German sagen "to say").
Watkins has this from a PIE *sokwyo-, from a root *sekw- (3) "to say, utter" (source also of Hittite shakiya- "to declare," Lithuanian sakyti "to say," Old Church Slavonic sociti "to vindicate, show," Old Irish insce "speech," Old Latin inseque "to tell say"). Some further see this as identical to the PIE root *sekw- (1) "to follow" (with semantic development to "see" and then "speak"). But others doubt it and Boutkan gives it "No certain PIE etymology."
The past tense form said developed from Old English segde. Impersonal use (it is said) was in Old English. The notion in shall we say, etc. (1580s) is "suppose, take for granted." On that analogy, impersonal say is used as an introduction word, or parenthetically, with a clause and meaning "suppose, assume" (c. 1600). Its colloquial use as an expression of surprise, etc. is by 1830.
Not attested before 1930 in use with inanimate objects (clocks, signs, etc.) as subjects. You said it! "you're right" is attested by 1919; you can say that again as a phrase expressing agreement is by 1925, American English colloquial. You don't say(so) as an expression of astonishment (often ironic) is attested by 1779. The Society of American Florists' advertising slogan say it with flowers dates to 1918 from it grew other say it with constructions.
Old English læfan "to allow to remain in the same state or condition; to let remain, allow to survive; to have left (of a deceased person, in reference to heirs, etc.); to bequeath (a heritage)," from Proto-Germanic *laibjanan (source also of Old Frisian leva "to leave," Old Saxon farlebid "left over"), causative of *liban "remain" (source of Old English belifan, German bleiben, Gothic bileiban "to remain"), from PIE root *leip- "to stick, adhere."
The Germanic root seems to have had only the sense "remain, continue" (which was in Old English as well but has since become obsolete), which also is in Greek lipares "persevering, importunate." But this usually is regarded as a development from the primary PIE sense of "adhere, be sticky" (compare Lithuanian lipti, Old Church Slavonic lipet "to adhere," Greek lipos "grease," Sanskrit rip-/lip- "to smear, adhere to."
Originally a strong verb (past participle lifen), it early switched to a weak form. Meaning "go away, take one's departure, depart from; leave behind" (c. 1200) comes from notion of "leave behind" (as in to leave the earth "to die;" to leave the field "retreat"). From c. 1200 as "to stop, cease; give up, relinquish, abstain from having to do with; discontinue, come to an end;" also "to omit, neglect; to abandon, forsake, desert; divorce;" also "allow (someone) to go."
Colloquial use for "let, allow" is by 1840, said by OED to be chiefly American English. Not related to leave (n.). To leave out "omit" is from late 15c. To leave (something) alone is from c. 1400; to leave (something) be is from 1825. To leave (something/nothing) to be desired is from 1780. To leave it at that is from 1902. Leave off is from c. 1400 as "cease, desist" (transitive); early 15c. as "stop, make an end" (intransitive).
c. 1300, discoveren, "divulge, reveal, disclose, expose, lay open to view, betray (someone's secrets)," senses now obsolete, from stem of Old French descovrir "uncover, unroof, unveil, reveal, betray," from Medieval Latin discooperire, from Latin dis- "opposite of" (see dis-) + cooperire "to cover up, cover over, overwhelm, bury" (see cover (v.)).
At first with a sense of betrayal or malicious exposure (discoverer originally meant "informant"). Also in Middle English used in lteral senses, such as "to remove" (one's hat, the roof from a building). The meaning "to obtain the first knowledge or sight of what was before not known," the main modern sense, is by 1550s.
Discover, Invent, agree in signifying to find out; but we discover what already exists, though to us unknown; we invent what did not before exist: as, to discover the applicability of steam to the purposes of locomotion, and to invent the machinery necessary to use steam for these ends. ... Some things are of so mixed a character that either word may be applied to them. [Century Dictionary]
Sense of "make famous or fashionable" is by 1908. Related: Discovered; discovering.
That man is not the discoverer of any art who first says the thing; but he who says it so long, and so loud, and so clearly, that he compels mankind to hear him—the man who is so deeply impressed with the importance of the discovery that he will take no denial, but at the risk of fortune and fame, pushes through all opposition, and is determined that what he thinks he has discovered shall not perish for want of a fair trial. [Sydney Smith, in Edinburgh Review, June 1826]
mid-14c., "opposite, opposed, at the opposite point or in the opposite direction; extremely unlike, most unlike," from Anglo-French contrarie, Old French contrarie, and directly from Latin contrarius "opposite, opposed; contrary, reverse," from contra "against" (see contra). Meaning "given to contradiction, perverse, intractable" is from late 14c.; sense of "adverse, unfavorable" is from late 14c. Related: Contrarily.
As a noun from late 13c., "one of a pair of characters, propositions, terms, etc., the most different possible within the same class." The phrase on the contrary "in precise or extreme opposition to what has been said" is attested from c. 1400 as in the contrary.
If we take the statement All men are mortal, its contrary is Not all men are mortal, its converse is All mortal beings are men, & its opposite is No men are mortal. The contrary, however, does not exclude the opposite, but includes it as its most extreme form. Thus This is white has only one opposite, This is black, but many contraries, as This is not white, This is coloured, This is dirty, This is black; & whether the last form is called the contrary, or more emphatically the opposite, is usually indifferent. But to apply the opposite to a mere contrary (e.g. to I did not hit him in relation to I hit him, which has no opposite), or to the converse (e.g. to He hit me in relation to I hit him, to which it is neither contrary nor opposite), is a looseness that may easily result in misunderstanding; the temptation to go wrong is intelligible when it is remembered that with certain types of sentence (A exceeds B) the converse & the opposite are identical (B exceeds A). [Fowler]
Middle English putten, from late Old English *putian, "to thrust, push, shove" (someone or something; a sense now obsolete), also "to move or a thing physically so as to place it in some situation," implied in putung "instigation, an urging," literally "a putting;" related to pytan "put out, thrust out" (of eyes), probably from a Germanic stem that also produced Danish putte "to put," Swedish dialectal putta; Middle Dutch pote "scion, plant," Dutch poten "to plant," Old Norse pota "to poke."
Obsolete past tense form putted is attested 14c.-15c. From c. 1300 as "to hurl, cast, propel," especially "to throw with an upward and forward motion of the arm" (Will. Putstan is attested as a name from 1296). From mid-14c. in the figurative sense of "bring (someone) into some specified state or condition;" late 14c. as "subject (someone to something)," as in put to death, c. 1400; put to shame, mid-15c. From mid-14c. as "make a declaration, express in speech or writing," hence "express or state (in a particular way)," 1690s, also "propose or place before someone for consideration."
To put (something) back is from 1530s as "to hinder, delay;" 1816 as "restore to the original place or position." To put (something) down "end by force or authority" (a rebellion, etc.) is from mid-14c. To put upon (someone) "play a trick on, impose on" is from 1690s. To put up with "tolerate, accept, bear or suffer without protest or resentment" (1755) is perhaps from put up "to take up" (one's lodgings, etc.), 1727. To put (someone) up in the transitive sense of "lodge and entertain" is by 1766. To put (someone) on "deceive" is from 1958. To put upon (someone) "play a trick on, deceive, impose on" is from 1690s.
c. 1200, reisen, "cause a rising of; lift upright, set upright; build, construct, bring into being," from a Scandinavian source, such as Old Norse reisa "to raise," from Proto-Germanic *raizjan (source also of Gothic ur-raisjan, Old English ræran "to rear;" see rear (v.)), causative of root *ris- "to rise" (see rise (v.)). At first sharing many senses with native rear (v.1).
Meaning "make higher" is from c. 1300 in the physical sense, as is that of "restore to life." Of the voice, from late 14c. Of sieges, blockades, etc., "remove by or as if by lifting," from late 14c. From early 14c. as "take up by aggregation or collection." The sense of "establish contact with (someone)," originally by radio, is by 1929. Meaning "to elevate" (the consciousness) is from 1970. Related: Raised; raising.
Meaning "increase the amount of" is from c. 1500; from 1530s of prices, etc. Meaning "to bring up" (a question, etc.) is from 1640s. Card-playing sense is from 1821. In reference to plants, etc., "promote with care the growth or development of," from 1660s; sense of "foster, rear, bring up" (of children) is by 1744.
Pickering ["A Vocabulary, or Collection of Words and Phrases Which Have Been Supposed to be Peculiar to the United States of America," 1816] has a long passage on the use of raise and grow in reference to crops. He writes that in the U.S. raise is used of persons, in the sense "brought up," but it is "never thus used in the Northern States." Bartlett  adds that it "is applied in the Southern States to the breeding of negroes. It is sometimes heard at the North among the illiterate; as 'I was raised in Connecticut,' meaning brought up there."
c. 1300, doctour, "Church father," from Old French doctour and directly from Medieval Latin doctor "religious teacher, adviser, scholar," in classical Latin "teacher," agent noun from docere "to show, teach, cause to know," originally "make to appear right," causative of decere "be seemly, fitting" (from PIE root *dek- "to take, accept").
Meaning "holder of the highest degree in a university, one who has passed all the degrees of a faculty and is thereby empowered to teach the subjects included in it" is from late 14c. Hence "teacher, instructor, learned man; one skilled in a learned profession" (late 14c.).
The sense of "medical professional, person duly licensed to practice medicine" (replacing native leech (n.2)) grew gradually out of this from c. 1400, though this use of the word was not common until late 16c. The transitional stage is exemplified in Chaucer's Doctor of phesike (Latin physica came to be used extensively in Medieval Latin for medicina).
That no man ... practyse in Fisyk ... but he be Bacheler or Doctour of Fisyk, havynge Lettres testimonyalx sufficeantz of on of those degrees of the Universite. [Rolls of Parliament, 1421]
Middle English also used medicin for "a medical doctor" (mid-15c.), from French. Similar usage of the equivalent of doctor is colloquial in most European languages: Italian dottore, French docteur, German doktor, Lithuanian daktaras, though these typically are not the main word in those languages for a medical healer. For similar evolution, compare Sanskrit vaidya- "medical doctor," literally "one versed in science." German Arzt, Dutch arts are from Late Latin archiater, from Greek arkhiatros "chief healer," hence "court physician." French médecin is a back-formation from médicine, replacing Old French miege, from Latin medicus.
Phrase what the doctor ordered "just the thing" is attested by 1914.