มะโรง • (má-roong)
From Old Khmer roṅ or roṅa, "dragon (zodiac)". Compare Angkorian Old Khmer roṅ; Modern Khmer រោង (roŭng). The first syllable, má, is interpolated.
Also compare Chinese 龍 (OC *b·roŋ, *mroːŋ, “dragon”).