combining form used from 19c. to represent Latin latus "the side, flank of humans or animals, lateral surface," a word of uncertain origin. The Latin word also was used to express intimacy, attachment, or relationship via the notion of "attach to the side, at the side of."

word-forming element meaning "toward or on the right-hand side," from combining form of Latin dexter (from PIE root *deks- "right, opposite of left; south").