Longman Dictionary of Contemporary English - whack

~1 v informal 1 to hit someone or something hard  (Ow! You whacked me with your elbow!) 2 spoken to put something somewhere  (Just whack it under the grill for a couple of minutes.) ~2 n especially spoken 1 the act of hitting something hard or the noise this makes 2 have a whack at to try to do something 3 do your whack BrE to do a fair or equal share of a job or activity  (I've done more than my whack of the driving - it's your turn.) 4 (the) full whack BrE the full amount  (You don't have to pay full whack if you're unemployed.) 5 at/in one whack AmE all on one occasion  (Steve lost $500 at one whack.) 6 out of whack AmE if a system, machine etc is out of whack, the parts are not working together correctly