Speaker of the line "Tomorrow, and tomorrow, and tomorrow / Creeps in this petty pace from day to day" (7)
I believe the answer is:
macbeth
(Other definitions for macbeth that I've seen before include "He doth murder sleep (Shak.)" , "King of Scotland, 1040-1057" , "Shakespeare play" , "play with tragic results" , "its name must not be mentioned" .)