backwater valve
noun
a valve for preventing flowing liquid, as sewage, from reversing its direction.
Nearby words
backward heart failure, backwardation, backwards, backwash, backwater, backwater valve, backwind, backwoods, backwoodsman, backword, backwrap
Also called backflow valve.
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019