1791, in oxalic acid, a violently poisonous substance found in many plants and used in dyeing, bleaching, and printing, from French oxalique (1787, Lavoisier), literally "of or pertaining to sorrel," from Latin oxalis "sorrel," from Greek oxalis, from oxys "sharp" (from PIE root *ak- "be sharp, rise (out) to a point, pierce"). So called because it occurs in sorrel and was first isolated from it.
1731, "clever, sharp, smart," shortening of acute; informal sense of "pretty" is by 1834, American English colloquial and student slang. Related: Cutely; cuteness.
"ear of grain," c. 1300, from Latin spica "ear of grain," from PIE *spei-ko-, from suffixed form of root *spei- "sharp point" (see spine).
in rhetoric, "a figure conjoining words or terms apparently contradictory so as to give point to the statement or expression," 1650s, from Greek oxymōron, noun use of neuter of oxymōros (adj.) "pointedly foolish," from oxys "sharp, pointed" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + mōros "stupid" (see moron). The word itself is an illustration of the thing. Now often used loosely to mean "contradiction in terms." Related: Oxymoronic.
late 13c., "strenuous, ardent, fierce, angry," from Old French aigre "sour, acid; harsh, bitter, rough; eager greedy; lively, active, forceful," from Vulgar Latin *acrus (source also of Italian agro, Spanish agrio), from Latin acer "keen, sharp, pointed, piercing; acute, ardent, zealous" (from PIE root *ak- "be sharp, rise (out) to a point, pierce").
Meaning "full of keen desire" (early 14c.) seems to be peculiar to English. The English word kept a secondary meaning of "pungent, sharp-edged" till 19c. (as in Shakespeare's "The bitter clamour of two eager tongues," in "Richard II"). Related: Eagerly; eagerness. Eager beaver "glutton for work" [OED] is from 1943, U.S. armed forces slang.
1590s, "sharp and painful, poignant, piercing," originally figurative, of pain or grief, from Latin pungentem (nominative pungens), present participle of pungere "to prick, pierce, sting," figuratively, "to vex, grieve, trouble, afflict" (from suffixed form of PIE root *peuk- "to prick"). For sense development, compare piquant; sharp (adj.).
Meaning "having powerful odor or taste, sharply affecting the sense of smell" is recorded by 1660s; in reference to writing, etc., "sharply affecting the mind, curt and expressive" is by 1850. The literal sense of "sharp, pointed" (c. 1600) is very rare in English and mostly limited to botany.
Middle English and early Modern English also had a now-obsolete verb punge "to prick, pierce; to smart, cause to sting," from Latin pungere. Related: Pungently.
"with the hands on the hips and the elbows bent outward at sharp angles," c. 1400, in kenebowe, of unknown origin, perhaps from Middle English phrase in keen bow "at a sharp angle" (with keen in its Middle English sense of "sharp" + bow "arch"), or from a Scandinavian word akin to Icelandic kengboginn "bow-bent," but this seems not to have been used in this exact sense. Middle English Compendium compares Old French chane/kane/quenne "can, pot, jug." Many languages use a teapot metaphor for this, such as Modern French faire le pot a deux anses "to play the pot with two handles."
1707, in fencing, "a quick thrust made after parrying a lunge," from French riposte, etymologically, "a response," by dissimilation from risposte (17c.), from Italian risposta "a reply," noun use of fem. past participle of rispondere "to respond," from Latin respondere "respond, answer to, promise in return" (see respond). Sense of "sharp retort; quick, sharp reply," is attested by 1865, on the notion of "a counter-stroke." As a verb, by 1851.
"sharp pain," c. 1200, from smart (adj.). Cognate with Middle Dutch smerte, Dutch smart, Old High German smerzo, German Schmerz "pain."
early 14c., from Old French vinaigre "vinegar," from vin "wine" (from Latin vinum; see wine (n.)) + aigre "sour" (see eager). In Latin, it was vinum acetum "wine turned sour," acetum for short (see acetic), also used figuratively for "wit, shrewdness;" and compare Greek oxos "wine vinegar," which is related to oxys "sharp" (from PIE root *ak- "be sharp, rise (out) to a point, pierce"). Related: Vinegary; vinegarish.