intransitive verb
or cos·teen käˈstēn, ˈ ̷ ̷ˌ ̷ ̷
( -ed/-ing/-s )
Etymology: from (assumed) Cornish costēn, probably from codha to fall, happen + stēn tin; akin to Old Norse hitta to hit, find — more at hit , stannum
Britain : to dig trenches or small pits through the surface soil or debris to the underlying rock in place for the purpose of exposing the outcrop of a mineral deposit and determining its course