American writer with essay in verse (6)
I believe the answer is:
poetry
'verse' is the definition.
(I know that verse can be written as poetry)
'american writer with essay' is the wordplay.
'american writer' becomes 'poe' (Edgar Allan Poe).
'with' is a charade indicator (letters next to each other).
'essay' becomes 'try' (synonyms).
'poe'+'try'='POETRY'
'in' acts as a link.
(Other definitions for poetry that I've seen before include "Verses" , "'Best words in best order' (Coleridge)" , "Literary art" , "Metrical writing" , "Verse" .)