Is sore (5)
I believe the answer is:
aches
'is sore' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aches that I've seen before include "Pains, hurts" , "Dull prolonged pains" , "Gives a dull pain" , "Constant pains" , "discomfort" .)