American footballer’s mother dressed in hard-wearing fabric (7)
I believe the answer is:
lineman
'american footballer's' is the definition.
(I've seen this before)
'mother dressed in hard-wearing fabric' is the wordplay.
'mother' becomes 'ma' (ma is a kind of mother).
'dressed in' is an insertion indicator.
'hard-wearing fabric' becomes 'linen'.
'ma' going within 'linen' is 'LINEMAN'.
(Other definitions for lineman that I've seen before include "Railway track worker" , "rail worker" , "American footballer" .)