Definition of "whack"
whack
/wæk/
noun
plural whacks
(dated, disco-era drug slang) PCP, phencyclidine (as also wack).
verb
third-person singular simple present whacks, present participle whacking, simple past and past participle whacked
(sports) To beat convincingly; to thrash.
adjective
comparative whacker, superlative whackest
Alternative form of wack (“crazy”)