Definition of "bencher"

There is Pump Court and Fountain Court, with their hydraulic apparatus, but one never heard of a bencher disporting in the fountain; and can’t but think how many a counsel learned in the law of old days might have benefited by the pump.

1848 November – 1850 December, William Makepeace Thackeray, chapter 30, in The History of Pendennis. […], volumes (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850

ten of them Aldermen, or chief Benchers

1719, Elias Ashmole, The Antiquity of Berkshire

Come, come, you are well understood to be a perfecter / giber for the table than a necessary bencher in the / Capitol.

c. 1605–1608, William Shakespeare, Coriolanus, act 2, scene 1, lines 76–78