dial. form of TRUNDLE sb. Also in comb. trunnel-head, a circular plate or disk at the head of a coke-oven or in a furnace; trunnel-hole, the aperture or throat of a puddling furnace in which this disk works.
1868. Joynson, Metals, 16. The opening at the top of the furnace, called the throat or trunnel-hole.
18[?]. Amer. Manuf., LXII. 626 (Cent. Suppl.). The trunnel-head, or ring, is a much more important part of a coke oven than most people imagine.
