Possible Clues:

• Irish poet who won the Nobel prize for literature in 1923
• Check back about English poet
• William Butler . . . . ., great poet
• Irish Nobelist in literature
• 'Sailing to Byzantium' writer
• "Lake Isle of Innisfree" poet
• Poet certainly needs a little time inside
• Guy about to come across English poet
• Literature Nobelist William Butler ___
• Poet who won the 1923 Nobel Prize for Literature