Worn by centre from Sheffield United (5)
I believe the answer is:
fused
'united' is the definition.
(similar in meaning)
'worn by centre from sheffield' is the wordplay.
'worn' becomes 'used' (I've seen this in another clue).
'by' is a charade indicator (letters next to each other).
'centre from' indicates the central letters.
The middle of 'sheffield' is 'f'.
'used' after 'f' is 'FUSED'.
(Other definitions for fused that I've seen before include "Joined by melting" , "Stuck together" , "Melted together" , "Coalesced" , "Welded together by heat" .)