Where does “ǵʰh₂u-mo-” come from?

ǵʰh₂u-mo- (Proto-Indo-European) comes from Proto-Indo-European ǵʰeh₂w- — to yawn, gape; to gape, yawn.

Ancestry of “ǵʰh₂u-mo-”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	ǵʰeh₂w-	to yawn, gape; to gape, yawn

ǵʰh₂u-mo- — Etymology, Origin & Word History | Etymology Explorer