have a whack at something Definition

whack (colloq)
verb

whacked, whacking
1. To hit something or someone sharply and resoundingly.

Thesaurus: clobber, hit, smack, lambaste, buffet, cuff, strike, whale (US), wallop, slap, slug, rap.

noun

1. A sharp resounding blow.

Thesaurus: hit, smack, blow, buffet, slug, belt, bash, sock, slap, crack, wallop, rap.
2. The sound of this.

Thesaurus: smack, bash, slap, crack, wallop, rap.
3. One's share of the profits or work, etc.

Example: haven't had their whack yet

Idiom: have a whack at something

To try it; to have a go at it.
Thesaurus: attempt, try, endeavour, give it a shot, give it a try.

Idiom: out of whack

(specially Austral & US)
Out of order.

Idiom: top whack ((the) full whack)

The highest price, wage or rate, etc.

Etymology: 18c: imitating the sound.