knock

1 a hard strike with a part of the body or an instrument gave the door a good knock Synonyms bang, bash, bat, beat, belt, biff, bop, box, buffet, bust, chop, clap, clip, clout, crack, cuff, dab, douse [British], fillip, hack, haymaker, hit, hook, blow, larrup [dialect], lash, lick, pelt, pick, plump, poke, pound, punch, rap, slam, slap, slug, smack, smash, sock, spank, stinger, stripe, stroke, swat, swipe, switch, thud, thump, thwack, wallop, welt, whack, wham, whop (also whap)Related Words counter, counterblow, counterpunch, counterstroke; body blow, hand, kick, knee, left, one-two, rabbit punch, right, right-hander, roundhouse, shiver, sidewinder, sucker punch, swing, uppercut; cruncher, kayo, knockdown, knockout, KO; bastinado (or bastinade), battering, beating, bludgeoning, clobbering, cudgeling (or cudgelling), drubbing, hammering, lambasting, licking, pasting, pounding, pummeling (also pummelling), thrashing; flogging, walloping, whip, whipping

2 bad luck or an example of this getting his college degree was a six year adventure not without its share of knocks along the way Synonyms adversity, ill, misfortune, misadventure, mischance, mishap, tragedyRelated Words calamity, cataclysm, catastrophe, disaster; affliction, hardship, trial, tribulation, woe; distress, misery, suffering, unhappiness; defeat, failure, fizzle, nonsuccess; curse, evil, sorrow, trouble; accident, casualty; blow, body blow, disappointment, letdown, setback; circumstance, destiny, doom, fate, lot, portionNear Antonyms break, chance, fluke, godsend, hit, opportunity, strike, stroke, windfall; accomplishment, achievement, successAntonyms fortune, luck, serendipity

3 a change in status for the worse usually temporarily the geneticist's reputation took a knock when several of his peers were unable to confirm his research findings Synonyms reverse, lapse, reversal, setbackRelated Words disappointment, frustration, letdown; comedown, decline, descent, down, downfall, fall; turnabout, turnaround; recession, regression, retrogression, reversion; relapse; breakdown, collapse, crash, meltdown, ruin, undoingNear Antonyms status quo

1 to come into usually forceful contact with something my knee knocked against the table leg when I tried to get up quickly Synonyms bang, bash, bump, collide, crash, impact, impinge, hit, ram, slam, smash, strike, swipe, thudRelated Words bounce, carom, clunk, glance, rebound, ricochet, skim, skip; contact, land, touch; brush, graze, kiss, nudge, scrape, shave, sweep; bulldoze, jostle, muscle, press, pushNear Antonyms miss, skirt

2 to deliver a blow to (someone or something) usually in a strong vigorous manner threatened to knock him upside the head if he didn't do as he was told Synonyms bang, bash, bat, belt, biff, bludgeon, bob, bonk, bop, box, bust, clap, clip, clobber, clock, clout, crack, hammer, hit, nail, paste, pound, punch, rap, slam, slap, slog, slug, smack, smite, sock, strike, swat, swipe, tag, thump, thwack, wallop, whack, whale, zapRelated Words batter, beat, buffet, bung, chop, cuff, drub, lace, lambaste (or lambast), lick, mangle, maul, pelt, pepper, pommel, pummel, rough; scuff; bunt, flick, stroke, tap; bump, butt, jab, jostle, kick, knee, poke, prod, push, shove, stamp; bowl (down or over), cream, deck, dump [slang], fell, floor, knock down, level; rabbit-punch, sucker punch; cane, club, cudgel, flail, flog, lash, sap, slash, sledge, sledgehammer, spear, stab, switch, thrash, whip; bean, brain, conk, skull

3 to express one's unfavorable opinion of the worth or quality of hey, don't knock it until you've tried it Synonyms blame, censure, condemn, denounce, dis (also diss) [slang], dispraise, fault, criticize, pan, reprehend, slag [chiefly British]Related Words skewer, tweak; assail, attack, blast, clobber, slam, slash; nick (at), snipe (at); beef, bellyache, bitch, carp, cavil, complain, crab, croak, fuss, gripe, grouse, growl, grumble, kick, kvetch, moan, murmur, mutter, niggle, quibble, whine; admonish, chide, drub, rebuke, reprimand, reproach, reprove; berate, castigate, crucify, excoriate, flay, gibbet, hammer, keelhaul, lambaste (or lambast), lash, pillory, scold, upbraid; bad-mouth, belittle, decry, deride, discommend, disparage, put downNear Antonyms approve, commend, endorse (also indorse), recommend, sanctionAntonyms extol (also extoll), laud, praise