Decoration made of smooth foil (4,5)
I believe the answer is:
iron cross
'decoration' is the definition.
(I've seen this before)
'smooth foil' is the wordplay.
'smooth' becomes 'iron' (to smooth down with an iron).
'foil' becomes 'cross' (synonyms).
'iron'+'cross'='IRON CROSS'
'made of' is the link.
(Other definitions for iron cross that I've seen before include "German military medal" , "foreign decoration" , "European award" , "German wartime medal" , "honour" .)