Fruit horse possibly ignored at first (5)
I believe the answer is:
apple
'fruit' is the definition.
(apple is a kind of fruit)
'horse possibly ignored at first' is the wordplay.
'horse possibly' becomes 'dapple' (term for a horse with dappled skin).
'ignored at first' means to remove the first letter.
'dapple' with its first letter taken away is 'APPLE'.
(Other definitions for apple that I've seen before include "Eg, Bramley, Braeburn" , "Granny Smith, for one" , "Jonathan, for example" , "The - Cart (Shaw)" , "Common fruit" .)