v. & n. colloq.
--v.tr.
1. strike or beat forcefully with a sharp blow.
2 (as whacked adj.) esp. Brit. tired out; exhausted.
--n.
1. a sharp or resounding blow.
2 sl. a share.
Phrases and idioms:
have a whack at sl. attempt. out of whack esp. US sl. out of order; malfunctioning.
Derivatives:
whacker n. whacking n.
Etymology: imit., or alt. of THWACK