It's leonine, but may be horsy (4)
I believe the answer is:
mane
'leonine but may be horsy' is the definition.
I can't judge whether this defines the answer.
'it's' is the wordplay.
I cannot quite see how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
The remaining letters 'man' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for mane that I've seen before include "(Lion's) hair on neck" , "Neck hair of an animal" , "Long thick hair" , "Hair (of lion)" , "Animal neck-hair" .)