/ Thesaurus / U Synonyms of undetectable Find synonyms for: Adjective1. undetectable, invisible (vs. visible), unseeableusage: not easily seen2. indiscernible, insensible, undetectable, imperceptible (vs. perceptible), unperceivableusage: barely able to be perceived; "the transition was almost indiscernible"; "an almost insensible change"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: candor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language