im ‧ pe ‧ tus /ˈɪmpətəs, ˈɪmpɪtəs/ BrE AmE noun [uncountable]
[ Date: 1600-1700 ; Language: Latin ; Origin: impetere 'to attack' , from petere 'to go to, look for' ]
1 . an influence that makes something happen or makes it happen more quickly
impetus for
The report may provide further impetus for reform.
The discovery gave fresh impetus to the research.
2 . technical the force that makes an object start moving, or keeps it moving