Lat″er‐al (?), a. [L. lateralis, fr. latus, lateris, side: cf. F. latéral.] 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.