Men box with hawk-headed god in ensemble (9)
I believe the answer is:
orchestra
'ensemble' is the definition.
(thesaurus)
'men box with hawk-headed god' is the wordplay.
'men' becomes 'OR' (Other Ranks: non-commissioned soldiers).
'box' becomes 'chest' (chest is a kind of box).
'with' is a charade indicator (letters next to each other).
'hawk-headed god' becomes 'ra' (Egyptian god).
'or'+'chest'+'ra'='ORCHESTRA'
'in' is the link.
(Other definitions for orchestra that I've seen before include "in four sections" , "Big band" , "Large music group" , "bandsmen?" , "Large musical group" .)