Gray, for one (7)
I believe the answer is:
'gray for one' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elegist that I've seen before include "Kind of writer" , "Writer of mournful verse" , "Poet, e.g. Gray" , "Writer of reflective poems" , "bemoaning linesman" .)