Costeaning

n. The process by which miners seek to discover metallic lodes. It consist in sinking small pits through the superficial deposits to the solid rock, and then driving from one pit to another across the direction of the vein, in such manner as to cross all the veins between the two pits. [ 1913 Webster ]

v. i. [ Cornish cothas dropped + stean tin. ] To search after lodes. See Costeaning. [ 1913 Webster ]