/im"pi teuhs/ , n. , pl. impetuses .
1. a moving force; impulse; stimulus: The grant for building the opera house gave impetus to the city's cultural life.
2. (broadly) the momentum of a moving body, esp. with reference to the cause of motion.
[ 1650-60; impetitus (though the expected form would be * impetitus; see APPETITE), equiv. to impeti-, var. s. of impetere to attack ( im- IM- 1 + petere to make for, assault) + -tus suffix of v. action ]
Syn. 1. stimulation, spur, boost.