/ məˈmentəm; NAmE moʊˈm-/ noun [ U ]
1.
the ability to keep increasing or developing :
The fight for his release gathers momentum each day.
They began to lose momentum in the second half of the game.
2.
a force that is gained by movement :
The vehicle gained momentum as the road dipped.
3.
( technical ) the quantity of movement of a moving object, measured as its mass multiplied by its speed
••
WORD ORIGIN
late 17th cent.: from Latin , from movimentum , from movere to move.