From *ᄃᆞᆺ (tòs, “warm”) + ᄒᆞ다 (hota). See also ᄃᆞᆺᄃᆞ시 (tòs-tòs-ì, “warmly”). ᄃᆞᆺ (tos-) would give rise to the modern coordinate terms for "warm", evolving through various forms derived from it. ᄃᆞᄉᆞ (toso-) would emerge through epenthesis of a second vowel and would result in ᄃᆞᄉᆞᆸ (tosop-), ᄃᆞᄉᆞ롭 (tosolwop-) and ᄃᆞᄉᆞᄒᆞ다 (tosohota) through the addition of different suffixes. Reduplication would lead to ᄃᆞᆺᄃᆞᆺᄒᆞ다 (tostoshota), attaining a consonant cluster that would undergo various vowel shifts in order to result in 따뜻하다 (ttatteuthada), 따끈하다 (ttakkeunhada) and 따갑 (ttagap-), as well as their respective variations. The ablauted form 듯 (tus-) and the reduplicated 듯듯ᄒᆞ다 (tustushota) resulted in 뜨뜻하다 (tteutteuthada) and 뜨끈하다 (tteukkeunhada) as well as 뜨겁 (tteugeop-) through rebracketing of its first syllable. Arae-aᆞwould undergo its vowel shift in each of these terms and the consonant clusters would be glottalized into /t͈/.[1]
ᄃᆞᆺᄒᆞ다〮 (tòshòtá)