Source : Webster's Revised Unabridged Dictionary (1913)

Oyer \O"yer\, n. [Anglo F., a hearing, from OF. o["i]r, F.
   ou["i]r, to hear, L. audire. See {Audible}.] (Law)
   A hearing or an inspection, as of a deed, bond, etc., as when
   a defendant in court prays oyer of a writing. --Blackstone.

   {Oyer and terminer} (Law), a term used in England in
      commissions directed to judges of assize about to hold
      court, directing them to hear and determine cases brought
      before them. In the U.S. the phrase is used to designate
      certain criminal courts.