nutty as a fruitcake
91lunatic — [adj] crazy, mad absurd, baked*, balmy*, bananas*, bonkers*, cracked, crazed, daft, demented, deranged, dippy*, flaky*, flipped out*, foolish, freaked out*, fried*, idiotic, insane, irrational, kooky*, loco, maniac, maniacal, nonsensical, nutty* …
