(Variations: box or college or factory or foundry or hatch may replace house) A mental hospital; insane asylum: He has been recalled by the nut college/ goes away to the nut house/ exceptional privacy and independence even in a nut hatch/ a general air of having been redecorated by a parolee from a nut hatch (entry form 1920s+, box 1960s+, college 1934+, factory 1915+, foundry 1932+, hatch 1940s+)