Struggles with mat (3)
I believe the answer is:
rug
'mat' is the definition.
(floor covering)
'struggles with' is the wordplay.
'with' says the answer is hidden in the clue.
'RUG' can be found hidden inside 'struggles'.
(Other definitions for rug that I've seen before include "Wig (informal)" , "Mat, carpet" , "wrap" , "Mat or knee-cover" , "grace the boards" .)