1. zonk - Noun
2. zonk - Verb
(slang) An unfavorable card or token, or undesirable or worthless item used as a prize in a contest or game show (such as Let's Make a Deal).
(slang) The feeling of a drug taking hold.
(slang) A cigarette hand-rolled from tobacco and cannabis.
(transitive, slang) To hit hard [1950].
(transitive, slang) To make (someone) sleepy or delirious, to put into a stupor [1968].
(intransitive, slang, usually followed by “out”) To become exhausted, sleepy or delirious.
After two hours of studying, I zonked out.