Requests gratify endlessly (5)
I believe the answer is:
pleas
'requests' is the definition.
(plea is a kind of request)
'gratify endlessly' is the wordplay.
'gratify' becomes 'please' (pleasing is a kind of gratifying).
'endlessly' means to remove the last letter.
'please' with its final letter taken away is 'PLEAS'.
(Other definitions for pleas that I've seen before include "Excuses, pretexts" , "Entreats" , "Urgent entreaties" .)