Etymology, French, Monsieur
Etymology From mon (“my”) + sieur, from the oblique case of Old French sire (see also French sire), from Vulgar Latin *seior (“lord, elder”), from Latin senior (“older, elder”) (whence also seigneur, from the accusative form), from senex (“old”),from Proto-Indo-European *sénos (“old”). Pronunciation IPA(key): /mə.sjø/, (archaic, sometimes used jocularly) /mɔ.sjø/, (obsolete) /mɔ̃.sjø/ Noun monsieur m (plural messieurs) mister, sir (a…