US writer to attempt verse (6)
I believe the answer is:
poetry
'verse' is the definition.
('poetry' can be a synonym of 'verse')
'us writer to attempt' is the wordplay.
'us writer' becomes 'poe' (I've seen this before).
'to attempt' becomes 'try' ('try' can be a synonym of 'attempt').
'poe'+'try'='POETRY'
(Other definitions for poetry that I've seen before include "Metrical writing" , "showing lyrical quality" , "'Best words in best order' (Coleridge)" , "Verse" , "'The Raven'?" .)