Thomas Gray, for one
I believe the answer is:
'thomas gray for one' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for elegist that I've seen before include "Gloomy poet" , "Poet, e.g. Gray" , "Writer of reflective poems" , "Mournful poet" , "Writer of mournful verse" .)