Some now restless to fight (7)
I believe the answer is:
wrestle
'fight' is the definition.
(thesaurus)
'some now restless to' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'WRESTLE' is hidden within 'now restless to'.
(Other definitions for wrestle that I've seen before include "Fight - get to grips (with)" , "Struggle physically or mentally" , "Tussle" , "Struggle (with a difficult problem)" , "Struggle, grapple" .)