A / arrūgĭa
noun

arrūgĭa

gen. arrūgiae · gender feminine · decl. 1st
akin to runco, runcina, ὀρύσσω, ὀρύξω, to dig; cf. Corssen, Ausspr. I. p. 543; v. corrugus
a shaft and pit in a gold-mine
a shaft and pit in a gold-mine, Plin. 33, 4, 21, § 70.