mid-15c., declinson, in grammar, "the inflection of nouns, pronouns, and adjectives, especially with a change in form from the nominative case," ultimately from Latin declinationem (nominative declinatio) "a bending from (something), a bending aside; a turning away from (something), an avoiding," also used in the grammatical sense, noun of action from past-participle stem of declinare "to lower; avoid, deviate; bend from, inflect," from de "from" (see de-) + clinare "to bend" (from PIE *klein-, suffixed form of root *klei- "to lean").
The immediate source of the English word is perhaps in French (compare Old French declinaison), but "the form is irregular, and its history obscure" [OED]. Meaning "a sloping downward" is from 1640s; that of "a sinking or falling into a lower or inferior state" is from c. 1600; that of "courteous refusal, non-acceptance" is by 1817. Related: Declensional.
mid-14c., "sternness, harshness," from Old French austerite "harshness, cruelty" (14c.) and directly from Late Latin austeritatem (nominative austeritas), from austerus "severe, rigid," a figurative use, in classical Latin "harsh, sour" (see austere).
From 1580s as "severe self-discipline, ascetic practices;" hence "severe simplicity, absence of adornment or luxuries," applied during World War II to national policies limiting non-essentials as a wartime economy.
[Austerity] stands just at the edge of that frame of mind which regards self-denial as good for its own sake ; it pushes simplicity of living and the refusal of pleasure beyond what is deemed necessary or helpful to right living by the great mass of those who are equally earnest with the austere in trying to live rightly. [Century Dictionary]
mid-13c., "attempt to clear (someone) from blame, find excuses for," from Old French escuser (12c., Modern French excuser) "apologize, make excuses; pardon, exonerate," from Latin excusare "excuse, apologize, make an excuse for, plead as an excuse; release from a charge; decline, refuse, excuse the refusal of" (source also of Spanish excusar, Italian scusare), from ex "out, away" (see ex-) + causa "accusation, legal action" (see cause (n.)).
Sense of "forgive, pardon, accept another's plea of excuse" is from early 14c. Meaning "to obtain exemption or release from an obligation or duty; beg to be excused" is from mid-14c. in English, as is the sense "defend (someone or something) as right." Sense of "serve as justification for" is from 1530s. Related: Excused; excusing. Excuse me as a mild apology or statement of polite disagreement is from c. 1600.
negative particle, a word expressing negation, denial, refusal, or prohibition, mid-13c., unstressed variant of noht, naht "in no way" (see naught). As an interjection to negate what was said before or reveal it as sarcasm, it is attested by 1900, popularized 1989 by "Wayne's World" sketches on "Saturday Night Live" TV show.
Not, spoken with emphasis, often stands for the negation of a whole sentence referred to: as, I hope not (that is, I hope that the state of things you describe does not exist). [Century Dictionary, 1895]
To not know X from Y (one's ass from one's elbow, shit from Shinola, etc.) was a construction attested from c. 1930 in modern use; but compare Middle English not know an A from a windmill (c. 1400). Double negative construction not un- was derided by Orwell, but is persistent and ancient in English, popular with Milton and the Anglo-Saxon poets.
type of betting card game involving a hand of three cards, 1670s, short for lanterloo (1660s), from French lanturelu, originally (1620s) the refrain of a popular comic song; according to French sources the refrain expresses a mocking refusal or an evasive answer and was formed on the older word for a type of song chorus, turelure; apparently a jingling reduplication of loure "bagpipe" (which is perhaps from Latin lura "bag, purse").
From its primary signification — a kind of bagpipe inflated from the mouth — the word 'loure' came to mean an old dance, in slower rhythm than the gigue, generally in 6-4 time. As this was danced to the nasal tones of the 'loure,' the term 'loure' was gradually applied to any passage meant to be played in the style of the old bagpipe airs. ["Grove's Dictionary of Music and Musicians," London, 1906]
The refrain sometimes is met in English as turra-lurra. In the game, also the name of the pool or kitty of chips deposited by players before seeing their hands, or of the deposit made in it by a player.
c. 1300, "stretched out (on a surface), prostrate, lying the whole length on the ground;" mid-14c., "level, all in one plane; even, smooth;" of a roof, "low-pitched," from Old Norse flatr "flat," from Proto-Germanic *flata- (source also of Old Saxon flat "flat, shallow," Old High German flaz "flat, level," Old High German flezzi "floor"), from PIE root *plat- "to spread."
From c. 1400 as "without curvature or projection." Sense of "prosaic, dull" is from 1570s, on the notion of "featureless, lacking contrast." Used of drink from c. 1600; of women's bosoms by 1864. Of musical notes from 1590s, because the tone is "lower" than a given or intended pitch. As the B of the modern diatonic scale was the first tone to be so modified, the "flat" sign as well as the "natural" sign in music notation are modified forms of the letter b (rounded or square).
Flat tire or flat tyre is from 1908. Flat-screen (adj.) in reference to television is from 1969 as a potential technology. Flat-earth (adj.) in reference to refusal to accept evidence of a global earth, is from 1876.
Old English strican (past tense strac, past participle stricen) "pass lightly over, stroke, smooth, rub," also "go, move, proceed," from Proto-Germanic *strikan- (source also of Old Norse strykva "to stroke," Old Frisian strika, Middle Dutch streken, Dutch strijken "to smooth, stroke, rub," Old High German strihhan, German streichen), from PIE root *strig- "to stroke, rub, press" (see strigil). Related to streak and stroke, and perhaps influenced in sense development by cognate Old Norse striuka.
Sense of "to deal a blow" developed by early 14c.; meaning "to collide" is from mid-14c.; that of "to hit with a missile" is from late 14c. Meaning "to cancel or expunge" (as with the stroke of a pen) is attested from late 14c. A Middle English sense is preserved in strike for "go toward." Sense of "come upon, find" is from 1835 (especially in mining, well-digging, etc., hence strike it rich, 1854). Baseball sense is from 1853. To strike a balance is from the sense "balance accounts" (1530s).
Meaning "refuse to work to force an employer to meet demands" is from 1768, perhaps from notion of striking or "downing" one's tools, or from sailors' practice of striking (lowering) a ship's sails as a symbol of refusal to go to sea (1768), which preserves the verb's original sense of "make level, smooth."
c. 1200, gelus, later jelus, "possessive and suspicious," originally in the context of sexuality or romance (in any context from late 14c.), from Old French jalos/gelos "keen, zealous; avaricious; jealous" (12c., Modern French jaloux), from Late Latin zelosus, from zelus "zeal," from Greek zēlos, which sometimes meant "jealousy," but more often was used in a good sense ("emulation, rivalry, zeal"), from PIE root *ya- "to seek, request, desire" (see zeal). In biblical language (early 13c.) "tolerating no unfaithfulness." Also in Middle English sometimes in the more positive sense, "fond, amorous, ardent" (c. 1300) and in the senses that now go with zealous, which is a later borrowing of the same word, from Latin.
Most of the words for 'envy' ... had from the outset a hostile force, based on 'look at' (with malice), 'not love,' etc. Conversely, most of those which became distinctive terms for 'jealousy' were originally used also in a good sense, 'zeal, emulation.' [Buck, pp.1138-9]
Among the ways to express "jealous" in other tongues are Swedish svartsjuka, literally "black-sick," from phrase bara svarta strumpor "wear black stockings," also "be jealous." Danish skinsyg "jealous," literally "skin-sick," is from skind "hide, skin" said to be explained by Swedish dialectal expression fa skinn "receive a refusal in courtship."