Badger; horse (3)
I believe the answer is:
nag
I believe this is a double definition.
'badger' is the first definition.
(I've seen this before)
'horse' is the second definition.
(term for an old horse)
(Other definitions for nag that I've seen before include "Scold like an old horse" , "Equine" , "Complain to or badger incessantly" , "Keep worrying" , "Badger continually like old horse" .)