An entertaining amateur actor (6)
I believe the answer is:
player
'actor' is the definition.
('player' can be a synonym of 'actor')
'an entertaining amateur' is the wordplay.
'an' becomes 'per' (synonymous as in 'once an hour', 'once per hour').
'entertaining' is an insertion indicator.
'amateur' becomes 'lay' ('lay' can be similar in meaning to 'amateur').
'per' going around 'lay' is 'PLAYER'.
(Other definitions for player that I've seen before include "Participant in competitive game" , "Gambler" , "film, on piano" , "Actor - musician" , "Important participant" .)