The word "momentum" means the force or energy gained by an object as it moves. It refers to the strength and speed of an object in motion. Full definition
Whether in combat or simply traveling around the city you're always keeping up a sort of momentum of moving around the place as fast as possible and some new additions help with that. (monstervine.com)
Analysts said there was unlikely to have been a change in momentum in the last two weeks of the month. (afr.com)
... As the invitations went out it gained momentum of its own, which was really quite exciting. (teachermagazine.com.au)