Follow a pet (3)
I believe the answer is:
dog
I believe this is a double definition.
'follow' is the first definition.
(dog can mean to follow or torment)
'a pet' is the second definition.
(I know that dog is a type of pet)
(Other definitions for dog that I've seen before include "Follow closely; animal" , "Contemptible man" , "Hound" , "Shadow" , "Worry" .)