early 15c., from Middle French latéral and directly from Latin lateralis "belonging to the side," from latus (genitive lateris) "side" (see oblate (n.)). As a noun, from 1630s, "a side part." As a type of pass to the side in U.S. football, it is attested from 1934. Related: Laterally.[lateral etymology, lateral origin, 英语词源]