Flawless finish (7)
I believe the answer is:
perfect
This clue is a double definition.
'flawless' is the first definition.
(similar in meaning)
'finish' is the second definition.
(perfect can mean to finish off and make perfect)
(Other definitions for perfect that I've seen before include "Without blemish" , "Mature" , "Exemplary" , "Getting by scheming" , "Complete" .)