Soldiers do so fully clothed (5)
I believe the answer is:
dress
'clothed' is the definition.
Both the answer and definition are adjectives. Perhaps you can see a link between them that I can't see?
'soldiers do so fully' is the wordplay.
I cannot really understand how this works, but
'soldiers' could be 're' (Royal Engineers) and 're' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dress that I've seen before include "female garment" , "Shift" , "Adorn" , "formal wear" , "Put on one's clothes" .)