English

Adjective

out to lunch

1. Away eating lunch or for a midday break; especially, away from work or a job.

   She's out to lunch right now, but you may leave her a note.

2. (idiomatic, informal) Clueless, inattentive, or careless.

   After he drove with his turn signal on for five miles, I was pretty sure he was out to lunch.

Usage notes

• May also be used as an adverb.