Look brave holding the man back (6)
I believe the answer is:
behold
'look' is the definition.
(thesaurus)
'brave holding the man back' is the wordplay.
'brave' becomes 'bold' ('bold' can be similar in meaning to 'brave').
'holding' means one lot of letters goes inside another.
'the man' becomes 'he'.
'back' is a reversal indicator.
'he' reversed gives 'eh'.
'bold' placed around 'eh' is 'BEHOLD'.
(Other definitions for behold that I've seen before include "See! Look!" , "Look at with attention" , "Lo, see here" , "Archaic word for see or observe" , "See, with attention" .)