By surface analysis, ᥛᥫᥒᥰ (möeng, “country”) + ᥗᥭᥰ (thäy, “Thai”). Cognate with with Thai เมืองไทย (mʉʉang-tai, “Thailand”).
ᥛᥫᥒᥰ ᥗᥭᥰ (möeng thäy) (1963 orthography ᥛᥫᥒ̈ ᥗᥭ̈)