/ Thesaurus / S Synonyms of sheath knife Find synonyms for: Noun1. case knife, sheath knife, knifeusage: a knife with a fixed blade that is carried in a sheathWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: effervescent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language