Eduro, edûras, pe. pro. edurâre. Col. To make very hard.
Lewis and Short: Latin dictionary
ē-dūro, āre, 1, v. n. and a.1.Neut., to last out, continue, endure (post-Aug. and very rare): solis fulgor in ortus edurat, Tac. G. 45: ulla effigies litterarum, Gell. 14, 1, 18.—2.Act., to harden, Col. 11, 1, 7.