That elegiac poet (4)
I believe the answer is:
gray
'that elegiac poet' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for gray that I've seen before include "a bit gloomy for the Americans" , "In America, dull" , "Author of ballad opera" , "Elegiac poet" , "An Anatomist; an Elegist" .)