Indelible design for a military display (6)
I believe the answer is:
tattoo
This clue could be a double definition.
'indelible design' is the first definition.
'tattoo' can be an answer for 'design' (tattoo is a kind of design). I am not certain of the 'indelible' bit.
'military display' is the second definition.
(I've seen this before)
'for a' is the link.
Can you help me to learn more?
(Other definitions for tattoo that I've seen before include "Design on skin - military show" , "Indelible decoration on skin" , "Personal design" , "Drum signal, display" , "Military display - picture on the skin" .)