Liberal Dictionary English Dictionary
adjective, kook·i·er, kook·i·est. Slang.
- of, like, or pertaining to a kook; eccentric, strange, or foolish.
adjective kookier or kookiest
- informal crazy, eccentric, or foolish
1959, American English, originally teenager or beatnik slang, possibly a shortening of cuckoo.
Using the newest show-business jargon, Tammy [Grimes] admits, “I look kooky,” meaning cuckoo. [“Life” magazine, Jan. 5, 1959]
Related: Kookily; kookiness.