Definition of "momentum"

momentum

/ˌmə(ʊ)ˈmɛntəm/

noun
countable and uncountable, plural momentums or momenta
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.
  Quotations
  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
  Their intention to become husband and wife, at first halting and timorous, had accumulated momentum with the lapse of hours, till it now bore down every obstacle in its course.
  1882, Thomas Hardy, chapter II, in Two on a Tower. A Romance. [...] In Three Volumes, volume II, London: Sampson Low, Marston, Searle, & Rivington, […], page 31
  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 ...
  2013 September 14, Jane Shilling, “The Golden Thread: the Story of Writing, by Ewan Clayton, review [print edition: Illuminating language]”, in The Daily Telegraph (Review)‎, page R29