Found 2 items, similar to loony.
English → English (WordNet) Definition: loony loony adj : informal or slang terms for mentally irregular; “it used to drive my husband balmy” [syn: balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kooky, kookie, loco, loopy, nuts, nutty, round the bend, around the bend , wacky, whacky] [also: looniest, loonier] loony n : someone deranged and possibly dangerous [syn: crazy, looney, weirdo] [also: looniest, loonier]
English → English (gcide) Definition: loony loony \loon"y\ (l[=oo]n"[y^]), a. [Shortened fr. lunatic.] 1. Crazy; insane; lunatic; mentally unsound. [Low, U.S.] [Written also loony, luny and looney.] See Luny. [1913 Webster] 2. Very foolish; very impractical; as, loony ideas. [PJC] loony \loon"y\ (l[=oo]n"[y^]), a. [Shortened fr. lunatic.] 1. Crazy; insane; lunatic; mentally unsound. [Low, U.S.] [Written also loony, luny and looney.] See Luny. [1913 Webster] 2. Very foolish; very impractical; as, loony ideas. [PJC] loony \loony\ (l[=oo]n"[y^]) n. someone mentally deranged and possibly dangerous. Syn: crazy, looney, weirdo, psycho. [WordNet 1.5] Luny \Lu"ny\, a. [Shortened fr. lunatic.] Crazy; insane; mentally unsound. [Written also loony and looney.] [Low, U.S.] [1913 Webster]