/ Thesaurus / C Synonyms of clapper valve Find synonyms for: Noun1. clack valve, clack, clapper valve, valveusage: a simple valve with a hinge on one side; allows fluid to flow in only one directionWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language