Ōr’tho-di-ăg’o-nal, n.
n. [Gr. ὀρθός, straight, and Eng. diagonal, q. v.] (Crystallog.) The diagonal or lateral axis in a monoclinic solid which is at right angles with the vertical axis. Dana.
n. [Gr. ὀρθός, straight, and Eng. diagonal, q. v.] (Crystallog.) The diagonal or lateral axis in a monoclinic solid which is at right angles with the vertical axis. Dana.