• (a.) Crazy; mentally unsound.
Lu'ny adjective [ Shortened from lunatic .] Crazy; mentally unsound. [ Written also loony .] [ Low, U.S.]
loony, looney, luny 1. An offensive term that deliberately insults someone's intelligence and ability to act rationally. 2. someone who behaves in an eccentric or thoughtless way. 3. A shortening, informal, and alterated version of lunatic.