"To Autumn," for one (4)
I believe the answer is:
poem
'to autumn for one' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for poem that I've seen before include "Mope (anag.)" , "Literary composition, sometimes in verse" , "Eg, If-" , "Piece of verse" , "Rhyme" .)