Military display of design on skin (6)
I believe the answer is:
tattoo
I believe this is a double definition.
'military display' is the first definition.
(I've seen this before)
'design on skin' is the second definition.
(I've seen this in another clue)
'of' is the link.
(Other definitions for tattoo that I've seen before include "that leaves a permanent impression on one" , "Drum signal; skin marking" , "Indelible picture or design on skin" , "Military evening signal" , "Design marked on skin" .)