word-forming element in medical use since 17c., taken as a combining form of Latin labium "lip" (see lip (n.)).

before vowels, lac-, word-forming element used in chemistry and physiology from 19c. and meaning "milk," from Latin lac (genitive lactis) "milk," from Proto-Italic *(g)lagt-, from PIE root *g(a)lag- "milk." This and the separate root *melg- (source of milk (n.)) account for words for "milk" in most of the Indo-European languages. The absence of a common word for it is considered a mystery. Middle Irish lacht, Welsh llaeth "milk" are loan words from Latin.

word-forming element in zoology, from combining form of larva (q.v.).

word-forming element meaning "worshipper," from Greek -latres "worshipper of," related to latreia "worship" (see -latry).

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."

prefix in use from 1939 as a combining form of Latin, from ablative of Latin latinus. By 1958 as a combining form from Latino.

word-forming element meaning "worship of," used as an element in native formations from 19c. (such as bardolatry), from Greek -latreia "worship, service paid to the gods, hired labor," related to latron (n.) "pay, hire," latris "servant, worshipper," from PIE *le- (1) "to get" (see larceny).

instrumental word-forming element, the usual modern form of -el (1), a suffix originally used in Old English to form agent nouns.

word-forming element abstracted 20c. from dialect and in words meaning a regional or social variety of a language.

before vowels lepid-, word-forming element used since late 18c. in science with a sense of "scale" (of a fish, etc.), combining form of Greek lepis (genitive lepidos) "scale of a fish" (related to lepein "to peel;" see leper). As in lepidodendron (1819 in German), common fossil "club-moss tree" of the Carboniferous.