The word for today is…
impetus (noun) – 1. An impelling force; an impulse.
2. The force or energy associated with a moving body.
3. (a) Something that incites; a stimulus.
(b) Increased activity in response to a stimulus:
Source : The Free Dictionary
Etymology : Impetus comes from Latin, where it means “attack or assault”; the verb impetere was formed by combining the prefix in- with petere, meaning “to go to or seek.” Petere also gives us other words suggesting a forceful urging or momentum, such as appetite, perpetual, and centripetal. Impetus describes the kind of force that encourages an action (“the impetus behind the project”) or the momentum of an action already begun (“the meetings only gave impetus to the rumors of a merger”).
