also metre, "fundamental unit of length of the metric system," originally intended to be one ten-millionth of the length of a quadrant of the meridian, 1797, from French mètre (18c.), from Greek metron "measure," from PIE root *me- (2) "to measure." Developed by French Academy of Sciences for system of weights and measures based on a decimal system originated 1670 by French clergyman Gabriel Mouton.
"flesh of sheep used as food," c. 1300, mouton (c. 1200 as a surname), from Old French moton "mutton; ram, wether, sheep" (12c., Modern French mouton), from Medieval Latin multonem (8c.), probably [OED] from Gallo-Roman *multo-s, accusative of Celtic *multo "sheep" (source also of Old Irish molt "wether," Mid-Breton mout, Welsh mollt), which is perhaps from PIE root *mel- (1) "soft."
The same word also was borrowed into Italian as montone "a sheep," and mutton in Middle English also could mean "a sheep" (early 14c.). Transferred slang sense of "food for lust, loose women, prostitutes" (1510s) led to extensive British slang uses down to the present day for woman variously regarded as seeking lovers or as lust objects. Mutton chop "cut of mutton (usually containing a rib) for cooking" is from 1720; as a style of side whiskers from 1865, so called for the shape (narrow and prolonged at one end and rounded at the other).
famous winged horse in Greek mythology, also the name of an ancient northern constellation, late 14c., Pegase, from Latin, from Greek Pēgasos, usually said to be from pēgē "fountain, spring; a well fed by a spring" (plural pēgai), especially in reference to the "springs of Ocean," near which Medusa was said to have been killed by Perseus (Pegasus sprang from her blood). But this may be folk etymology, and the ending of the word suggests non-Greek origin.
Advances since the 1990s in the study of the Luwians, neighbors of the Hittites in ancient Anatolia, show a notable convergence of the Greek name with Pihaššašši, the name of a Luwian weather-god: "the mythological figure of Pegasus carrying the lightning and thunderbolt of Zeus, ... is likely to represent an avatar of the Luwian Storm-God of Lightning ...." [Alice Mouton, et al., eds., "Luwian Identities," 2013]