noun

1. an indefinitely brief period of time; instant
2. a definite point in time or in a series of events
3. a brief time of being important or outstanding
4. importance; consequence news of great moment
5. Mech. the product of some physical quantity and its distance from the origin of coordinates or an axis, as a torque
6. Philos. any constituent element of a complex entity or process

Etymology: ME < L momentum, movement, impulse, brief space of time, importance < *movimentum < movere, to move