impetus
Pronunciation:
/ˈɪm.pə.təs/noun
Definitions
Something that impels; a stimulating factor.
Example: The outbreak of World War II in 1939 gave a new impetus to receiver development.
A force, either internal or external, that impels; an impulse.
The force or energy associated with a moving body; a stimulus.
An activity in response to a stimulus.