cock·eyed adj. Informal

  1. Foolish; ridiculous; absurd: a cockeyed idea.
  2. Askew; crooked.
  3. Intoxicated; drunk.
This word could have come from the word Caoch, a Gaelic word meaning ‘one-eyed’.

Alternatively it could have come literally from cock ‘male chicken'. The word was used as a verb - cocken, meaning "to fight". Later it came to mean "to swagger" and after that it came to mean "to set in a jaunty way".

Cockeyed itself first appeared in 1821 meaning "squint eyed" and in 1896 it appeared meaning "silly or foolish".