/ Thesaurus / U Synonyms of unpassable Find synonyms for: Adjective1. impassable (vs. passable), unpassable, unsurmountable, unclimbable, unnavigable, untraversableusage: incapable of being passedWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language