Pay rises in Newmarket are numerous (10)
I believe the answer is:
remunerate
'pay' is the definition.
(remunerating is a kind of paying)
'rises in newmarket are numerous' is the wordplay.
'rises' is a reversal indicator.
'in' says the answer is hidden in the clue.
'etarenumer' is hidden within 'newmarket are numerous'.
'etarenumer' backwards is 'REMUNERATE'.
(Other definitions for remunerate that I've seen before include "reward" , "Pay for service" , "Make payment to" , "Pay (for work done)" .)