Bull or cow? Horse close (4,4)
I believe the answer is:
grey seal
'bull or cow?' is the definition.
I can't tell whether this definition defines the answer.
'horse close' is the wordplay.
'horse' becomes 'grey' (I've seen this before).
'close' becomes 'seal' (sealing is a kind of closing).
'grey'+'seal'='GREY SEAL'
Can you help me to learn more?
(Other definitions for grey seal that I've seen before include "N. Atlantic mammal" , "Sea creature" , "Marine mammal" , "North Atlantic mammal" .)