Decoration possibly made by an apprentice (5)
I believe the answer is:
medal
'decoration' is the definition.
(I know that decoration can be written as medal)
'possibly made by an apprentice' is the wordplay.
'possibly' indicates anagramming the letters.
'by' means one lot of letters go next to another.
'an apprentice' becomes 'L' (as in a learner driver with L-plates on their car).
'made' with letters rearranged gives 'meda'.
'meda'+'l'='MEDAL'
(Other definitions for medal that I've seen before include "Winner's award" , "Award for the soldier" , "Religious or commenorative metal piece" , "Olympic award" , "Commemorative disc" .)