Part of a dog's paw (3)
I believe the answer is:
pad
'part of a dog's paw' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for pad that I've seen before include "In slang, one's flat or bedsitter" , "Jotter; compress" , "Fill with extra material in order to lengthen" , "Protective guard; home" , "pack" .)