Remind persistently (3)
I believe the answer is:
nag
'remind persistently' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nag that I've seen before include "(Of pain) ache dully; horse (colloq.)" , "Worry; old horse" , "shrew or > badger" , "Ailing horse" , "Be persistently painful" .)