thwack

1 a hard strike with a part of the body or an instrument he gave the ball a hard thwack with the bat and sent it deep into the outfield 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, knock, 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, blow, 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 a loud explosive sound even from the top of the bleachers we could hear the loud thwack of the ball being hit Synonyms bang, blast, boom, crack, crash, pop, report, slam, smash, snap, thunderclap, clap, whack, whomp, whumpRelated Words thunk, wham; clang, clangor, clank, clash; knock, rap, tap; blare, clamor, howl, hubbub, hue and cry, hullabaloo, outcry, roar, tumult, uproar