Subsidiary angle (4)
I believe the answer is:
side
I believe this is a double definition.
'subsidiary' is the first definition.
(thesaurus)
'angle' is the second definition.
(thesaurus)
(Other definitions for side that I've seen before include "Airs and graces" , "group of players" , "Pomposity - bias - team" , "Face - team" , "perspective" .)