nut house

or nut·house

See more synonyms for nut house on Thesaurus.com

noun Slang.

a mental hospital; insane asylum.

Origin of nut house

First recorded in 1900–05

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for nuthouse

Contemporary Examples

So Peggy calls 911 and gets the loony copywriter sent off to the nuthouse.
Mad Men’s ‘The Runaways’: Three-Way Sex and Self-Mutilation in the Craziest Episode Yet
Marlow Stern
May 12, 2014

Historical Examples

I won't say I like this place—your world or the nuthouse entrance to it.
Shock Treatment
Stanley Mullen

British Dictionary definitions for nuthouse

nuthouse

noun

slang a mental hospital or asylum

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012