Mo preserves bronze with fallen head (7)
I believe the answer is:
instant
'mo' is the definition.
(I know that instant is a type of mo)
'preserves bronze with fallen head' is the wordplay.
I cannot really understand how this works, but
'bronze' could be 'tan' (both can mean to get a sun tan) and 'tan' is found within the answer.
The remaining letters 'inst' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for instant that I've seen before include "This coffee comes in powder form" , "Occurring immediately, like some fast food" , "Twinkling of a eye" , "Moment - this month" , "Mo" .)