From Proto-Tai *sajꟲ (“intestine”). Cognate with Thai ไส้ (sâi), Northern Thai ᩈᩱ᩶, Lü ᦺᦉᧉ (ṡay²), Shan သႆႈ (sāi), Aiton ꩬႝ (say), Phake ꩬႝ (say), Ahom 𑜏𑜩 (say), Tai Dam ꪼꪎ꫁, Zhuang saej. Compare Proto-Be *tseːᴮꟲ².
ໄສ້ • (sai)