מַעֲרָב m (ma'aráv, “west”) + ־וֹן (-on, “suffix forming denominative nouns”), from the root ע־ר־ב ('-r-b) forming words relating to west, and famous for עֶרֶב (érev, “evening”) (because the sun sets in the west).
מַעֲרָבוֹן • (ma'arávon) m (plural indefinite מַעֲרְבּוֹנִים)