/ Thesaurus / E Synonyms of endlessness Find synonyms for: Noun1. endlessness, duration, lengthusage: the property of being (or seeming to be) without endWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: illegible Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language