The main work of an artist? (8)
I believe the answer is:
seascape
This clue could be a double definition.
'the main work' is the first definition.
(I've seen this before)
'an artist' is the second definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'of' acts as a link.
(Other definitions for seascape that I've seen before include "Main work" , "View of ocean and sky" , "Painting, maybe a Turner" , "Marine view" , "Maritime scene" .)