'loony' definitions:

Definition of 'loony'

(from WordNet)
adjective
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, loony, loopy, nuts, nutty, round the bend, around the bend, wacky, whacky]
noun
Someone deranged and possibly dangerous [syn: crazy, loony, looney, nutcase, weirdo]

Definition of 'loony'

From: GCIDE
  • 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]

Definition of 'loony'

From: GCIDE
  • 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]

Definition of 'loony'

From: GCIDE
  • loony \loony\ (l[=oo]n"[y^]) n. someone mentally deranged and possibly dangerous.
  • Syn: crazy, looney, weirdo, psycho. [WordNet 1.5]

Definition of 'loony'

From: GCIDE
  • Luny \Lu"ny\, a. [Shortened fr. lunatic.] Crazy; insane; mentally unsound. [Written also loony and looney.] [Low, U.S.] [1913 Webster]

Words containing 'loony'