escape valve es·ca·pe·valve uncommon noun 1. a valve in a container in which pressure can build up (as a steam boiler); it opens automatically when the pressure reaches a dangerous level Synonymssafety valverelief valveescape valveescape cockescape Related words Broader terms valveregulator WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
