Possible Definitions:
1. Whack (v. t.) To divide into shares; as, to whack the spoils of a robbery; -- often with up.
2. Whack (n.) A portion; share; allowance.
3. Whack (v. t.) To strike; to beat; to give a heavy or resounding blow to; to thrash; to make with whacks.
4. Whack (v. i.) To strike anything with a smart blow.
5. Whack (n.) A smart resounding blow.