Goal wearing split dress (7)
I believe the answer is:
raiment
'dress' is the definition.
(synonyms)
'goal wearing split' is the wordplay.
'goal' becomes 'aim' (aim is a kind of goal).
'wearing' is an insertion indicator.
'split' becomes 'rent' (past tense of 'rend' meaning to split).
'aim' placed within 'rent' is 'RAIMENT'.
(Other definitions for raiment that I've seen before include "Clobber" , "Garment" , "Gear" , "Apparel" , "Tire man (anag.)" .)