Even the soldier assumes it (7)
I believe the answer is:
uniform
'even' is the definition.
(I've seen this before)
'soldier assumes it' is the wordplay.
I cannot quite see how this works, but
'soldier' could be 'rm' (Royal Marine) and 'rm' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'the' acts as a link.
Can you help me to learn more?
(Other definitions for uniform that I've seen before include "Always the same, unvarying." , "Distinctive clothing worn by a group" , "Identical - livery" , "Not varying, like army clothes" , "follower of tango on the radio?" .)