Where does “kh₁u-” come from?

kh₁u- (Proto-Indo-European) comes from Proto-Indo-European keh₁w- — to wobble, swing.

Ancestry of “kh₁u-”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	keh₁w-	to wobble, swing

kh₁u- — Etymology, Origin & Word History | Etymology Explorer