Speckled steed (4)
I believe the answer is:
roan
'speckled steed' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for roan that I've seen before include "nag" , "Horse with a coat of mixed colour" , "Horse - leather" , "Red-coloured horse" , "Type of 17's coat colouring" .)