Skin of brindled pattern (4)
I believe the answer is:
rind
'skin' is the definition.
('rind' can be a synonym of 'skin')
'of brindled pattern' is the wordplay.
'of' indicates the answer is hidden within the clue.
'RIND' is hidden in the letters of 'brindled pattern'.
(Other definitions for rind that I've seen before include "Cheese or fruit skin" , "thick skin" , "Tough outer layer" , "'Peel, bark (4)'" , "Hard outer skin, of an orange say" .)