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.

Source: Webster's Revised Unabridged Dictionary (1913)