momentum

The force or speed of movement; the driving force gained by a process or course of events; (physics) the quantity of motion of a moving body.

• (no common derivatives)

• gain momentum
• lose momentum
• build momentum
• political momentum
• momentum shift

1. 1.The reform movement gained momentum after thousands joined the march. (driving force)
2. 2.The team lost momentum after their star player was injured in the second quarter. (force/energy)

• impetus/ˈɪmpɪtəs/— a driving force — more formal
• drive/draɪv/— energy and determination
• thrust/θrʌst/— the principal purpose or force

from Latin "momentum" (movement, moving power) — "movimentum" — "movere" (to move)