/ Thesaurus / I Synonyms of impossibly Find synonyms for: Adverb1. impossiblyusage: to a degree impossible of achievement; "long thought to be an impossibly difficult operation"; "impossibly far from sources of supply"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: penury Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language