Breadcrumb Home > Thesaurus > M Synonyms of momentous Find synonyms for: Adjective 1. momentous, significant (vs. insignificant), important usage: of very great significance; "deciding to drop the atom bomb was a very big decision"; "a momentous event" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of momentous (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: rugose Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language