Source : Webster's Revised Unabridged Dictionary (1913)

Oyez \O"yez`\ ([=o]y[e^]s; 277), interj. [Anglo-F. oyez hear ye.
   See {Oyer}.]
   Hear; attend; -- a term used by criers of courts to secure
   silence before making a proclamation. It is repeated three
   times. [Written also {oyes}.]