Where does “หัวหอม” come from?

หัวหอม (Thai) comes from Thai หัว, from Proto-Tai truəᴬ — head.

หัวหอม (Thai): onion

Definitions

Step	Language	Word	Meaning
1	Thai	หัว	head; swelling; protuberance; bulb, tuber, or...
2	Proto-Tai	truəᴬ	head

หัวหอม — Etymology, Origin & Word History | Etymology Explorer