Sides (6)
I believe the answer is:
flanks
'sides' is the definition.
(I have seen 'Military sides ' mean 'flanks' so perhaps 'sides' could also mean 'flanks')
This is all the clue.
(Other definitions for flanks that I've seen before include "Haunches" , "Sides of body between ribs and hips" , "Military sides" , "The sides of an animal" .)