LOONY
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
(adjective) informal or slang terms for mentally irregular; “it used to drive my husband balmy”
crazy, loony, looney, nutcase, weirdo
(noun) someone deranged and possibly dangerous
Source: WordNet® 3.1
Etymology
Adjective
loony (comparative loonier, superlative looniest)
(informal, of a person) Insane.
(informal, of a thing) Very silly, absurd.
Synonyms
• See also insane
Noun
loony (plural loonies)
(informal) An insane or very foolish person.
Source: Wiktionary
Loon"y, a.
Definition: See Luny.
Source: Webster’s Unabridged Dictionary 1913 Edition