The Collaborative International Dictionary of English v.0.48:

Breakfast \Break"fast\, v. i. [imp. & p. p. breakfasted; p.
   pr. & vb. n. Breakfasting.]
   To break one's fast in the morning; too eat the first meal in
   the day.
   [1913 Webster]

         First, sir, I read, and then I breakfast. --Prior.
   [1913 Webster]