Founding. [Of obscure origin.] (See quots.) Also attrib.
Webster’s definition is probably erroneous.
1828–32. Webster, Sprue, in Scotland, that which is thrown off in casting metals; scoria.
1875. Knight, Dict. Mech., 1084/2. Head,… the sprue, sullage-piece, or riser on a casting, which is knocked off. Ibid. (1884), Suppl., Sprue Hole, a gate, ingate, or pouring-hole in a mold.
1884. W. H. Greenwood, Steel & Iron, 201. The smaller passages, often two or three in number, leading from the skimming gate to the mould are called sprues or sprue gates.
