From Proto-Tai *saːm (“three”), from Middle Chinese 三 (MC sam, “three”). Cognate with Thai สาม (sǎam), Northern Thai ᩈᩣ᩠ᨾ, Lao ສາມ (sām), Lü ᦉᦱᧄ (ṡaam), Tai Dam ꪎꪱꪣ, Shan သၢမ် (sǎam), Tai Nüa ᥔᥣᥛᥴ (sáam), Ahom 𑜏𑜪 (saṃ), Zhuang sam.
ส่าม (transliteration needed)