What is "lateral equation"

Lateral \Lat"er*al\, a. [L. lateralis, fr. latus, lateris, side: cf. F. lat['e]ral.]

1. Of or pertaining to the sides; as, the lateral walls of a house; the lateral branches of a tree.

2. (Anat.) Lying at, or extending toward, the side; away from the mesial plane; external; -- opposed to mesial.

3. Directed to the side; as, a lateral view of a thing.

   Lateral cleavage (Crystallog.), cleavage parallel to the lateral planes.

   Lateral equation (Math.), an equation of the first degree.

   Lateral line (Anat.), in fishes, a line of sensory organs along either side of the body, often marked by a distinct line of color.

   Lateral pressure or stress (Mech.), a pressure or stress at right angles to the length, as of a beam or bridge; -- distinguished from longitudinal pressure or stress.

   Lateral strength (Mech.), strength which resists a tendency to fracture arising from lateral pressure.

   Lateral system (Bridge Building), the system of horizontal braces (as between two vertical trusses) by which lateral stiffness is secured.