Poet or speaker as he develops (11)
I believe the answer is:
shakespeare
'poet' is the definition.
(Shakespeare is an example)
'speaker as he develops' is the wordplay.
'develops' indicates anagramming the letters.
'speaker'+'as'+'he'='speakerashe'
'speakerashe' is an anagram of 'SHAKESPEARE'.
'or' is the link.
(Other definitions for shakespeare that I've seen before include "The Bard of Avon" , "Author of Hamlet" , "Man of note" , "As writer he is performed" , "No 1 poet" .)