WordNet (r) 3.0 (2006):

snake pit
    n 1: any place of pain and turmoil; "the hell of battle"; "the
         inferno of the engine room"; "when you're alone Christmas
         is the pits"; [syn: hell, hell on earth, hellhole,
         snake pit, the pits, inferno]
    2: pejorative terms for an insane asylum [syn: Bedlam, booby
       hatch, crazy house, cuckoo's nest, funny farm, funny
       house, loony bin, madhouse, nut house, nuthouse,
       sanatorium, snake pit]