Promote mushy peas to nurse (4)
I believe the answer is:
hype
'promote' is the definition.
(I've seen this in another clue)
'mushy peas to nurse' is the wordplay.
'to nurse' indicates a hidden word (I've seen 'nurses' mean this (nurse can mean holding closely)).
'HYPE' is hidden in the letters of 'mushy peas'.
(Other definitions for hype that I've seen before include "injection" , "Shrewd publicity" , "Puffery" , "Publicity stunt" , "Agitate" .)