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 of momentum

• 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 momentum, and delirium, only lasted a couple of minutes, however, as Lake Creek’s Harper Montgomery headed in a loose ball in the goalkeepers box in the 74th minute to put the Lions back up 3-2. —Charles Baggarly & Darren Lauber, Fort Worth Star-Telegram, 11 Apr. 2026

The two special elections that flipped blue in March with the help of independent voters quickly served as a rallying cry for Democrats hoping to build momentum leading up to the November mid-term elections. —Jeffrey Schweers, The Orlando Sentinel, 11 Apr. 2026

Swalwell’s campaign has shown signs of momentum. —Lia Russell, Sacbee.com, 11 Apr. 2026

China’s push to modernize its tactical airlift fleet is gaining momentum with the emergence of its new medium-lift transport aircraft, commonly known as the Y-30 or Y-15. —Bojan Stojkovski, Interesting Engineering, 11 Apr. 2026

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