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

Ajay Mitchell Should Play Key Role Although his rookie season lost some momentum due to an injury that kept him out down the stretch of the regular season, Mitchell was undoubtedly one of the best rookies in last year’s class. —Nick Crain, Forbes.com, 20 July 2025

Roberts left the door open for Betts to sit Sunday, too, as the Dodgers hope their superstar can generate some positive offensive momentum. —Fabian Ardaya, New York Times, 20 July 2025

The phenomenon of Trump has now re-oriented thinking in Europe and Asia, shifted the momentum of the Russia-Ukraine war, shaken for the first time in decades the foundations of open global trade and put into question the dollar as the global reserve currency. —New York Daily News Editorial Board, New York Daily News, 20 July 2025

Such an abrupt halt to the WNBA's momentum could prove difficult to bounce back from. —Becky Sullivan, NPR, 19 July 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