momentous
adjective
mo·men·tous
mō-ˈmen-təs 
mə-
: having great or lasting importance : consequential, significant
a momentous decision
a momentous event/occasion
The Senate begins a momentous debate on health care today …—
The New York Times
The New York TimesDeydey usually talked about his travels, the places he'd seen and the people, the close calls and momentous encounters with animals, weather, other Anishinabeg, and best of all, ghosts.—Louise Erdrich
Louise ErdrichThe late nineteenth century was strewn with inventions. Many were momentous, but few affected men and women more closely than the bicycle and its motorized offspring: motorcycle, motor-car and aeroplane.—Eugen Weber
Eugen Weber
momentously
adverb
a momentously important decision
… a … twist that is executed differently from the comic book story, but is just as dramatically and momentously presented.
—The Philippines Daily Inquirer
The Philippines Daily Inquirer
momentousness
noun
But other East Europeans had little time to marvel at the momentousness of the moment. Just one day after the fall of the [Berlin] Wall, Bulgaria's dour leader of 35 years, Todor Zhivkov, was ousted.
—Stephen E. Deane
Stephen E. Deane
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
Amidst the momentous changes of her day, Carson not only fashioned a book that anticipated much that was yet to come and still to be debated.
—Literary Hub, 8 June 2026
In the seven years since Angie and Chris Long became fascinated with the 2019 FIFA Women’s World Cup in France, one momentous milestone has cascaded into another — both for the co-founders of the NWSL’s Kansas City Current and the city itself.
—Kansas City Star, 3 June 2026
Such a capability would be momentous, according to Mueller, who led the teams that developed SpaceX's workhorse Merlin engine and Draco thruster back in the day.
—Mike Wall, Space.com, 2 June 2026
First-quarter demand was strong after a momentous 2025.
—Stephen Garner, Footwear News, 1 June 2026
See All Example Sentences for momentous
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Literary Hub, 8 June 2026
In the seven years since Angie and Chris Long became fascinated with the 2019 FIFA Women’s World Cup in France, one momentous milestone has cascaded into another — both for the co-founders of the NWSL’s Kansas City Current and the city itself.
—Kansas City Star, 3 June 2026
Such a capability would be momentous, according to Mueller, who led the teams that developed SpaceX's workhorse Merlin engine and Draco thruster back in the day.
—Mike Wall, Space.com, 2 June 2026
First-quarter demand was strong after a momentous 2025.
—Stephen Garner, Footwear News, 1 June 2026
See All Example Sentences for momentous
Cite this Entry
“Momentous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/momentous. Accessed 8 Jun. 2026.
Copy CitationKids Definition
momentous
adjective
mo·men·tous
mō-ˈment-əs
: very important
a momentous decision
momentously
adverb
Love words? Need even more definitions?
Merriam-Webster unabridged
