What is "brachydiagonal"

Brachydiagonal \Brach`y*di*ag"o*nal\, a. [Gr. brachy`s short + E. diagonal.] Pertaining to the shorter diagonal, as of a rhombic prism.

Brachydiagonal axis, the shorter lateral axis of an orthorhombic crystal.

Brachydiagonal \Brach`y*di*ag"o*nal\, n. The shorter of the diagonals in a rhombic prism.

a. Relating to the shorter diagonal, as of a rhombic prism. n. The shorter of the diagonals in a rhombic prism.