1. Los Angeles, California (often abbreviated L.A.). This expression pokes fun at the alleged eccentricities of the city's in habitants. For example, What do you expect? Frederick has lived in la-la land for ten years and it has rubbed off on him. [Slang; c. 1980] 2. A state of being out of touch with reality, as in I don't know what's going on with Amy? she seems to be in la-la land. [Slang; c. 1980] Also see CLOUD-CUCKOO LAND; NEVER-NEVER LAND.
American Heritage Idioms