Source : Webster's Revised Unabridged Dictionary (1913)

Hey \Hey\, a. [See {High}.]
   High. [Obs.] --Chaucer.

Hey \Hey\, interj. [OE. hei; cf. D. & G. hei.]
   1. An exclamation of joy, surprise, or encouragement. --Shak.

   2. A cry to set dogs on. --Shak.