Where does “กอ” come from?

กอ (Thai) comes from Proto-Tai koːᴬ — clump {{q|as of bamboo}}.

Ancestry of “กอ”, step by step

Step	Language	Word	Meaning
1	Proto-Tai	koːᴬ	clump {{q\|as of bamboo}}

กอ — Etymology, Origin & Word History | Etymology Explorer