What is "to sleep away"

Sleep \Sleep\, v. t.

1. To be slumbering in; -- followed by a cognate object; as, to sleep a dreamless sleep.
   --Tennyson.

2. To give sleep to; to furnish with accomodations for sleeping; to lodge. [R.]
   --Blackw. Mag.

   To sleep away, to spend in sleep; as, to sleep away precious time.

   To sleep off, to become free from by sleep; as, to sleep off drunkeness or fatigue.