Hull, with English poetry's ultimate poet (7)
I believe the answer is:
shelley
'poet' is the definition.
(I've seen this before)
'hull with english poetry's ultimate' is the wordplay.
'hull' becomes 'shell' (shell is a kind of hull**).
'with' is a charade indicator (letters next to each other).
'english' becomes 'e' (abbreviation).
'ultimate' says to take the final letters.
The last letter of 'poetry' is 'y'.
'shell'+'e'+'y'='SHELLEY'
(Other definitions for shelley that I've seen before include "Author of Ode to the West Wind" , "English Romantic poet" , "Writer of To a skylark" , "Percy Bysshe . . . . . . ., great English poet" , "Ode to the West Wind poet" .)