Writer's detailed writing (3)
I believe the answer is:
poe
'writer's' is the definition.
(Edgar Allan Poe)
'detailed writing' is the wordplay.
'detailed' means to remove the last letter (the word must be end-less or 'de-tailed').
'writing' becomes 'poem' (poem is a kind of writing).
'poem' with its final letter removed is 'POE'.
(Other definitions for poe that I've seen before include "American author, d. 1849" , "The Raven writer" , "Author of The Murders in the Rue Morgue" , "Edgar Allan . . ., writer of spooky tales" , "Entrance rooms; seeks support from" .)