Fight saint on mat with broken leg (8)
I believe the answer is:
struggle
'fight' is the definition.
(synonyms)
'saint on mat with broken leg' is the wordplay.
'saint' becomes 'st'.
'on' says to put letters next to each other.
'mat' becomes 'rug' (I've seen this before).
'with' means one lot of letters go next to another.
'broken' indicates anagramming the letters.
'leg' with letters rearranged gives 'gle'.
'st'+'rug'+'gle'='STRUGGLE'
(Other definitions for struggle that I've seen before include "Uphill battle" , "Toil" , "pains" , "Make vigorous effort under difficulties" , "Contend with difficulty" .)