From Proto-Southwestern Tai *suəmꟲ (“room; compartment”). Cognate with Thai ส้วม (sûuam, “toilet”), Isan ส้วม (“bedroom”), Lao ສ້ວມ (sūam, “room; bedroom”).
ᥔᥧᥛᥳ (su̇m) (1963 orthography ᥔᥧᥛ̇)
Cognate with Thai ซุ้ม (súm), Shan သုမ်ႉ (sṵ̂m), Ahom 𑜏𑜤𑜪 (suṃ).