Costeaning is 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. ...
• (v. i.) To search after lodes. See Costeaning.
A trench cut across the conjectured line of outcrop of a seam or ore body to expose the full width.
Cos'tean` intransitive verb [ Cornish cothas dropped + stean tin.] To search after lodes. See Costeaning .