The Thai word kuai tiao is a borrowing from the Teochew variety of Chinese.
Thai kuai tiao, written ก๋วยเตี๋ยว, comes from the Teochew form guê diao, written 粿條. Teochew is a Southern Min variety associated with the Chaoshan region of Guangdong and with major overseas Chinese communities across Southeast Asia.
The borrowing reflects centuries of migration and culinary exchange rather than a purely Thai origin for the term. Related forms appear elsewhere in the region, including kuyteav in Cambodia, hủ tiếu in Vietnam, and kway teow in Malaysia and Singapore.
Mandarin, Hokkien, and Cantonese are plausible distractors because all have influenced Southeast Asian food vocabulary. Hokkien forms are especially close in some regional spellings, but the specific etymology given for Thai kuai tiao is Teochew.