[ moh-men-tuhm ]
See synonyms for momentum on
noun,plural mo·men·ta [moh-men-tuh], /moʊˈmɛn tə/, mo·men·tums.
  1. force or speed of movement; impetus, as of a physical object or course of events: The car gained momentum going downhill. Her career lost momentum after two unsuccessful films.

  2. Also called linear momentum .Mechanics. a quantity expressing the motion of a body or system, equal to the product of the mass of a body and its velocity, and for a system equal to the vector sum of the products of mass and velocity of each particle in the system.

  1. Philosophy. moment (def. 7).

Origin of momentum

First recorded in 1690–1700; from Latin mōmentum; see moment

Words that may be confused with momentum

Words Nearby momentum Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use momentum in a sentence

British Dictionary definitions for momentum


/ (məʊˈmɛntəm) /

nounplural -ta (-tə) or -tums
  1. physics the product of a body's mass and its velocity: Symbol: p See also angular momentum

  2. the impetus of a body resulting from its motion

  1. driving power or strength

Origin of momentum

C17: from Latin: movement; see moment

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for momentum


[ mō-mĕntəm ]

Plural momenta momentums
  1. A vector quantity that expresses the relation of the velocity of a body, wave, field, or other physical system, to its energy. The direction of the momentum of a single object indicates the direction of its motion. Momentum is a conserved quantity (it remains constant unless acted upon by an outside force), and is related by Noether's theorem to translational invariance. In classical mechanics, momentum is defined as mass times velocity. The theory of Special Relativity uses the concept of relativistic mass. The momentum of photons, which are massless, is equal to their energy divided by the speed of light. In quantum mechanics, momentum more generally refers to a mathematical operator applied to the wave equation describing a physical system and corresponding to an observable; solutions to the equation using this operator provide the vector quantity traditionally called momentum. In all of these applications, momentum is sometimes called linear momentum. See also angular momentum impulse.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for momentum


In physics, the property or tendency of a moving object to continue moving. For an object moving in a line, the momentum is the mass of the object multiplied by its velocity (linear momentum); thus, a slowly moving, very massive body and a rapidly moving, light body can have the same momentum. (See Newton's laws of motion.)

Notes for momentum

Figuratively, momentum can refer to the tendency of a person or group to repeat recent success: “The Bears definitely have momentum after scoring those last two touchdowns.”

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.