Definition of "wack" in English

adjective

1. (originally African-American Vernacular, slang) Annoyingly or disappointingly bad, in various senses; lousy, corny, cringy, uncool, messed up.

   • Every record they ever made was straight-up wack.

noun

1. An eccentric; an oddball; a weirdo.

2. (dated, 70s drug slang) PCP, phencyclidine (as also whack).

noun

1. (UK, Liverpool) A friendly term of address.