Frayed seam in uniform (4)
I believe the answer is:
same
'uniform' is the definition.
(synonyms)
'frayed seam' is the wordplay.
'frayed' indicates anagramming the letters.
'seam' with letters rearranged gives 'SAME'.
'in' acts as a link.
(Other definitions for same that I've seen before include "Equal in amount or value" , "uniform" , "If - be the food of love, play on (Twelfth Night)" , "Ditto" , "Aforesaid" .)