Diagonal \Di*ag"o*nal\, a. [L. diagonalis, fr. Gr. ? from to angle; dia` through + ? an angle; perh. akin to E. knee: cf. F. diagonal.]

(Geom.) Joining two not adjacent angles of a quadrilateral or multilateral figure; running across from corner to corner; crossing at an angle with one of the sides.

Diagonal bond (Masonry), herringbone work. See Herringbone, a.

Diagonal built (Shipbuilding), built by forming the outer skin of two layers of planking, making angles of about 45[deg] with the keel, in opposite directions.

Diagonal cleavage. See under Cleavage.

Diagonal molding (Arch.), a chevron or zigzag molding.

Diagonal rib. (Arch.) See Cross-springer.

Diagonal scale, a scale which consists of a set of parallel lines, with other lines crossing them obliquely, so that their intersections furnish smaller subdivisions of the unit of measure than could be conveniently marked on a plain scale.

Diagonal stratification. (Geol.) Same as Cross bedding, under Cross, a.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Diagonal \Di*ag"o*nal\, n.

1. A right line drawn from one angle to another not adjacent, of a figure of four or more sides, and dividing it into two parts.

2. (Engin.) A member, in a framed structure, running obliquely across a panel.

3. A diagonal cloth; a kind of cloth having diagonal stripes, ridges, or welts made in the weaving.

Source: Webster's Revised Unabridged Dictionary (1913)