Verses and essay by American author (6)
I believe the answer is:
poetry
'verses' is the definition.
(I've seen this before)
'essay by american author' is the wordplay.
'essay' becomes 'try' ('try' can be a synonym of 'essay').
'by' means one lot of letters go next to another.
'american author' becomes 'poe' (I've seen this before).
'try' put after 'poe' is 'POETRY'.
'and' acts as a link.
(Other definitions for poetry that I've seen before include "Metrical writing" , "showing lyrical quality" , "Literary art" , "'The Raven'?" , "Sonnets, limericks etc" .)