Longman Dictionary of Contemporary English
loony bin
noun
EXAMPLES FROM CORPUS
▪ Even if it wasn't quite enough finesse to keep him out of the loony bin.
▪ It was Day Release at the loony bin.
▪ Make one misstep marketing creamed corn and you could end up in the loony bin.
▪ On the floor above the loony bin, nobody quite knew what took place.
▪ Perhaps that means it's raising money for a loony bin.
▪ What kind of a loony bin have they got down there in Berkeley, anyway?
The Collaborative International Dictionary
loony bin
loony bin \loony bin\ (l[=oo]n"[y^] b[i^]n) n. An institution for the confinement or treatment of insane persons, such as an insane asylum or the psychiatric ward of a hospital. [slang]
Syn: mental institution.
Wiktionary
loony bin
alt. (context slang English) A lunatic asylum. n. (context slang English) A lunatic asylum.
WordNet
loony bin
n. pejorative terms for an insane asylum [syn: Bedlam, booby hatch, crazy house, cuckoo's nest, funny farm, funny house, madhouse, nut house, nuthouse, sanatorium, snake pit]