Rubbish overly military show (6)
I believe the answer is:
tattoo
'military show' is the definition.
(I've seen this before)
'rubbish overly' is the wordplay.
'rubbish' becomes 'tat' (I've seen this before).
'overly' becomes 'too' ('too' can be a synonym of 'overly').
'tat'+'too'='TATTOO'
(Other definitions for tattoo that I've seen before include "Drum signal; skin mark" , "Skin painting" , "Skin inking" , "Miltary call and design on the skin" , "one has to beat" .)