Blend of พู่ (pū, “person”) + ใด (dai, “which”). Cognate with Lao ໃຜ (phai) , Northern Thai ᨹᩲ, Lü ᦺᦕ (ṗhay), Shan ၽႂ် (phǎue), Tai Nüa ᥚᥬᥴ (pháue), Aiton ၸၞ် (phaü), Ahom 𑜇𑜧 (phaw) or 𑜇𑜨𑜧 (phow).
ใผ (transliteration needed)