momentum

noun

mo·​men·​tum mō-ˈmen-təm 

mə-

plural momenta mō-ˈmen-tə 

mə-

or momentums

1

: a property (see property sense 1a) of a moving body that the body has by virtue of its mass (see mass entry 2 sense 1c) and motion and that is equal to the product of the body's mass and velocity

broadly : a property of a moving body that determines the length of time required to bring it to rest when under the action of a constant force or moment

2

: strength or force gained by motion or by a series of events

The wagon gained momentum as it rolled down the hill.

Synonyms

• impetus
• incentive
• encouragement
• motivation
• stimulus

Examples of momentum in a Sentence

The company has had a successful year and hopes to maintain its momentum by introducing new products.

The movie loses momentum toward the end.

Recent Examples on the Web

The issue continues to gain momentum. —Mike Snider, USA Today, 4 Oct. 2025

In that context, Beckham’s frog loafers felt less like a gimmick and more like a continuation of the designer’s Paris momentum. —Maggie Clancy, Footwear News, 3 Oct. 2025

And the social-media outcry over Kimmel’s indefinite suspension and subsequent reinstatement might suggest that a new civil-liberties movement is gaining momentum. —Jay Caspian Kang, New Yorker, 3 Oct. 2025

And momentum is what carries you from one success to the next. —Sinéad O'Sullivan, CNBC, 3 Oct. 2025

Word History

Etymology

New Latin, from Latin, movement

First Known Use

1610, in the meaning defined at sense 1

Phrases Containing momentum

• angular momentum
• gather/gain momentum
• gather momentum/strength
• lose momentum
• pick up speed/momentum

Rhymes for momentum

• cementum
• omentum
• tegmentum
• tomentum
• argumentum
• sacramentum
• testamentum
• centum
• mentum

Kids Definition

momentum

noun

mo·​men·​tum mō-ˈment-əm 

plural momenta -ˈment-ə  or momentums

1

: the characteristic of a moving body that is caused by its mass and its motion

2

: impetus sense 1

Medical Definition

momentum

noun

mo·​men·​tum mō-ˈment-əm, mə-ˈment- 

plural momenta -ˈment-ə  or momentums

: a property of a moving body that the body has by virtue of its mass and motion and that is equal to the product of the body's mass and velocity

broadly : a property of a moving body that determines the length of time required to bring it to rest when under the action of a constant force