noun a smart resounding blow.
2. whack ·vi to strike anything with a smart blow.
3. whack ·add. ·noun a portion; share; allowance.
4. whack ·add. ·vt to divide into shares; as, to whack the spoils of a robbery;
often with up.
5. whack ·vt to strike; to beat; to give a heavy or resounding blow to; to thrash; to make with whacks.