From Proto-Tai *ɣaːᴬ (“thatch grass”). Cognate with Thai คา (kaa), Northern Thai ᨤᩣ, Lao ຄາ (khā), Lü ᦆᦱ (xaa), Shan ၶႃး (kháa), Ahom 𑜁𑜡 (khā). Compare Proto-Hlai *Ciɦaː (“thatch grass”) (> haː¹~zaː¹~hjaː¹ across the different lects), Sui yal (“thatch grass”).
ᥑᥣᥰ (xäa) (1963 orthography ᥑᥣ̈)