momentum

Etymology

From Latin mōmentum. Doublet of moment and movement.

noun

1. (physics) Of a body in motion: the tendency of a body to maintain its inertial motion; the product of its mass and velocity, or the vector sum of the products of its masses and velocities.
2. The impetus, either of a body in motion, or of an idea or course of events; a moment.
   The travellers swarm forth from the cars. All are full of the momentum which they have caught from their mode of conveyance. 1843, Nathaniel Hawthorne, Mosses from an Old Manse, The Old Apple Dealer
   Though his account of written communication over the past 5,000 years necessarily has a powerful forward momentum, his diversions down the fascinating byways of the subject are irresistible ... 14 September 2013, Jane Shilling, “The Golden Thread: the Story of Writing, by Ewan Clayton, review [print edition: Illuminating language]”, in The Daily Telegraph (Review), page R29