Other forms: whacked, whacking, whacks
To whack something is to hit it hard with a swinging blow. Whack it with a spade, gave it a whack, whacked the ball.
It is informal and slightly comic, and the sound is part of the word. As a noun a whack is the blow itself, and in British informal use it also means a share or a large amount: the full whack, paying top whack. Have a whack at something means to attempt it. Note out of whack, meaning out of proper order or alignment, which is American and now widely used everywhere.
1verbwhackTo hit hard with a swinging blow.
“He whacked the post back in with the flat of the spade.”
Too few real examples of this word to estimate which sense is commonest.
whack is a hard blow.
Whack is imitative, coined by ear like smack, thwack and crack. English has produced a steady supply of these hitting words, and most of them arrived without any traceable ancestry at all.
unknown. Originally Scottish; probably onomatopoeic, but compare Middle English thakken, from Old English þaccian (whence Modern thwack by conflation with whack). Sense 6 of the verb is likely a hentam.
Etymology from Wiktionary, CC BY-SA