1) American slang for to kill 2) Attempt 3) Belt 4) Bump off 5) Hit hard 6) Hit plenty hard 7) Hit with a bang 8) Often with up 9) Sharp blow 10) Slang for phencyclidine 11) Slap hard 12) Slang for heroin 13) Sound 14) Stab 15) Strike sharply 16) Take a paddle to 17) The act of hitting vigorously 18) To beat convincingly 1) Bat 2) Belt 3) Bop 4) Clobber 5) Hit 6) Ice 7) Lam 8) Punch 9) Slay 10) Smite 11) Stab 12) Strike 13) Swat 14) Thump 15) Wham 16) Whang 17) Whop 
• (v. t.) To divide into shares; as, to whack the spoils of a robbery; -- often with up. • (n.) A portion; share; allowance. • (n.) A smart resounding blow. • (v. t.) To strike; to beat; to give a heavy or resounding blow to; to thrash; to make with whacks. • (v. i.) To strike anything with a smart blow.Whack: words in the ...
to murder; see burn. 
Whack intransitive verb To strike anything with a smart blow. To whack away , Whack noun A smart resounding blow. [ Colloq.] Whack transitive verb [ imperfect & past participle Whacked ; present participle & verbal noun Whacking .] [ Confer Thwack .] To strike; to beat; to give a heavy or resounding blow to; to thrash; to make with whacks. [ Colloq.] �...
Whack is drug slang for phencyclidine.
[v] - hit hard
Fair share, agreed deal
noun the sound made by a sharp swift blow