1
general::
1. Stop functioning, fail, as in The engine finally conked out. [Colloquial; early 1900s] 2. Fall asleep, as in Every evening he conked out in front of the television set. [1940s] 3. Faint or collapse, as in I don't know if it was the heat, but she suddenly conked out. [1920s] 4. Die, as in He's paranoid about conking out and he's only twenty! [Late 1920s]
American Heritage Idioms
2
general::
Phrase(s): conk out
Go to conk off and conk out
McGrawhill's American Idioms And Phrasal Verbs