Front of some coin (5)
I believe the answer is:
brass
'front' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for brass that I've seen before include "Boldness" , "Nerve (but not of steel!)" , "Readies" , "Zinc-copper alloy - cheek" , "Gall" .)