Oyer and Terminer is in Legal Terms.
Oyer and Terminer. Literally "to hear and to determine". The Law French name for one of the commissions by which a judge of assize sat.
By 27 Jul 1453, says Griffiths, the situation in the north had deteriorated so badly that the crown effectively abrogated its authority in the region, by writing directly to the two earls [Note Henry Percy 2nd Earl of Northumberland (age 60) and Richard Neville 5th Earl Salisbury (age 53)], laying responsibility for ending the dispute on them, and instructing them to keep their sons in order. It was at this point too, that the commission of oyer and terminer of 12 July was re-issued.
Pepy's Diary. 17 Mar 1663. Up betimes and to my office a while, and then home and to Sir W. Batten (age 62), with whom by coach to St. Margaret's Hill in Southwark, Surrey [Map], where the judge of the Admiralty came, and the rest of the Doctors of the Civill law, and some other Commissioners, whose Commission of oyer and terminer was read, and then the charge, given by Dr. Exton, which methought was somewhat dull, though he would seem to intend it to be very rhetoricall, saying that justice had two wings, one of which spread itself over the land, and the other over the water, which was this Admiralty Court.
Pepy's Diary. 24 Oct 1663. It seems that, after the much talk of troubles and a plot, something is found in the North that a party was to rise, and some persons that were to command it are found, as I find in a letter that Mr. Coventry (age 35) read to-day about it from those parts1.
Note 1. This refers to a rising in the West Riding of Yorkshire, which took place on October 12th, and was known as the Farneley Wood Plot. The rising was easily put down, and several prisoners were taken. A special commission of oyer and terminer was sent down to York to try the prisoners in January, 1663-64, when twenty-one were convicted and executed. (See Whitaker's "Loidis and Elmete", 1816.).