Stories of immortal essayists (5)
I believe the answer is:
tales
'stories' is the definition.
('tale' can be a synonym of 'story')
'of immortal essayists' is the wordplay.
'of' says the answer is hidden in the clue.
'TALES' can be found hidden inside 'immortal essayists'.
(Other definitions for tales that I've seen before include "provided for defective juries" , "Stale kind of stories" , "Stories, fables" , "Stories, perhaps tall ones" , "Relations" .)