Synonyms of 'escape hatch'

alternative, back door, boundary condition, catch, choice, clause, condition, donnee, ejection seat, escalator clause, escape clause, fine print, fire escape, given, joker, kicker, lifeboat, lifeline, life buoy, life net, life raft, loophole, obligation, parameter, prerequisite, pretext, provision, proviso, requisite, sally port, sine qua non, slide, small print, specification, stipulation, string, ultimatum, underground, whereas