incentive
Concise Oxford English Dictionary © 2008 Oxford University Press:
incentive/ɪnˈsentɪv/
▶noun a thing that motivates or encourages someone to do something.
■ a payment or concession to stimulate greater output or investment.
– derivatives
incentivize (or incentivise) verb.
incentivize (or incentivise) verb.
– origin ME: from L. incentivum ‘something that sets the tune or incites’, from incantare ‘to chant or charm’.
'incentive' also found in these Oxford entries:

