Star able to work (7)
I believe the answer is:
canopus
'star' is the definition.
(I know that Canopus is a supergiant)
'able to work' is the wordplay.
'able' becomes 'can'.
'to work' becomes 'opus' (an opus is an artistic work).
'can'+'opus'='CANOPUS'
(Other definitions for canopus that I've seen before include "Second brightest star in the sky" , "Ancient Egyptian vase" , "A luminary" , "Ancient Egyptian funeral jar to hold entrails" , "Shiner" .)