mo·​men·​tous | \mō-ˈmen-təs, mə-\

Definition of momentous 

: important, consequential a momentous decision a momentous event

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Other Words from momentous

momentously adverb
momentousness noun

Examples of momentous in a Sentence

My college graduation was a momentous day in my life. a momentous occasion that will go down in the history books

Recent Examples on the Web

Some people think Timmy may win an Oscar for this film, which would be momentous. Cady Drell, Marie Claire, "This Week in Timothée Chalamet, October 12 Edition," 12 Oct. 2018 With a camera in tow, capture the locations of momentous events while learning more about Boston’s role in the Revolutionary War., "The Ticket: What’s happening in the local arts world," 28 June 2018 For Kim Jong Un, this momentous day was one for North Korea's history books that won't require exaggeration. Jamie Tarabay, CNN, "Kim had a great summit. And he didn't even need to give anything away," 12 June 2018 April 20 was a momentous day for the new Indian Trail Garden Learning Center, which was made possible by an anonymous donor. Karen Berkowitz,, "Rundown house becomes gardening lab after anonymous gift to Highland Park school," 24 Apr. 2018 The timing of the momentous occasion wasn't lost on him. Philip Marcelo, Fox News, "Social issues roiling US weigh heavy on Independence Day," 3 July 2018 The Drug Policy Alliance trumpeted Trump's remarks as another sign that America's attitudes toward marijuana have seen momentous change in the last decade. Dennis Romero /, NBC News, "Trump says he'll probably back marijuana protections bill," 9 June 2018 Smoked an Ashton Churchill in honor of a momentous occasion: Lucas Giolito didn’t walk anybody. Steve Rosenbloom,, "Yu Darvish: It's not that you’re on the DL — it’s that you’re not Jake Arrieta," 1 June 2018 Congratulations are certainly in order – to the graduates, and to the families, friends, teachers, and administrators who brought you to this momentous occasion. Katie Reilly, Time, "Rod Rosenstein Tells Law Graduates to Fall Back on ‘Your Own Moral Principles’ During Ethical Dilemmas," 11 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'momentous.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of momentous

1656, in the meaning defined above

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Statistics for momentous

Last Updated

14 Nov 2018

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Time Traveler for momentous

The first known use of momentous was in 1656

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More Definitions for momentous



English Language Learners Definition of momentous

: very important : having great or lasting importance


mo·​men·​tous | \mō-ˈmen-təs \

Kids Definition of momentous

: very important a momentous decision

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Comments on momentous

What made you want to look up momentous? Please tell us where you read or heard it (including the quote, if possible).


playful or foolish behavior

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