What does momentum mean?
Momentum is the impetus that keeps an action, person, or development moving forward, as in a campaign that gains momentum after an initial success. In physics, it has a precise meaning: the product of an object's mass and velocity, describing both the amount and direction of its motion. The everyday expression often suggests increasing energy, support, or progress, although it can also refer to momentum that is already strong or that is being lost. The word is useful because it describes not just whether something is moving, but the force and tendency behind its movement. It appears frequently in discussions of business, politics, research, campaigns, and public opinion. In formal scientific writing, the technical sense takes precedence and should be distinguished from speed, since a heavy object can have substantial momentum without moving quickly.
The quantity of motion in a body, equal to the product of its mass and velocity and represented by a vector quantity.
"The rolling ball transferred momentum to the stationary ball."
This is a technical physics term. The direction of the momentum vector is important.
The strength or impetus that keeps a person, organization, or process moving forward.
"The early victories gave the team the momentum to continue competing."
Common in figurative use; it can suggest increasing energy, support, or progress.
The formal plural is momenta. Momentum is also commonly used unchanged in the plural, especially in general writing.
"The two teams exchanged momenta before the final quarter, while the researchers compared the momenta of the particles."
In physics, momentum measures how much motion an object carries; in everyday speech, it names the invisible drive that turns a promising idea into a movement.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does momentum come from?
The word comes through English from Latin momentum, meaning “impulse” or “movement,” a noun formed from movēre, “to move.” Its scientific use developed in the 17th century as the quantity describing motion in a body. Modern figurative senses, referring to driving force or increasing development, grew from the idea of momentum as an impetus. The related English word moment has the same Latin root through a different formation.
Related word forms
How momentum is actually used
The figurative sense is common in political, business, academic, and social contexts. In physics, the term is technical and is not interchangeable with speed: an object can have considerable momentum while moving slowly if its mass is large.
Easily confused with momentum
A moment is a very brief period of time, whereas momentum is the impetus or driving force that keeps an action or process moving.
Impetus emphasizes the initial force that sets something in motion, while momentum can refer both to that force and to the continuing drive of a developing process.