From Proto-Balto-Slavic *mauˀras, from the stem Proto-Indo-European *mew-, *mow-, *mu- (“humidity; dirty wetness; to wash”), with an extra -r. The meaning evolved from “humid place” to “humid place where many plants grow”, “small plants of humid, swampy areas”, and finally “area covered with plants, grass”. Cognates include Lithuanian máuras, usually plural maurai̇̃, Russian мурава́ (muravá, “grass, lawn”), dialectal мура (mura, “small plants; piece of land covered with low vegetation and flooded during spring”), Ukrainian мурина́ (muryná, “miry, swampy place after flooding”), Ancient Greek μύρω (múrō, “to flow”), μύρομαι (múromai, “to cry”).