Where does “hluchoněmý” come from?

hluchoněmý (Czech) comes from Czech -o-, from Old Czech -o-.

hluchoněmý (Czech): deaf-mute

Definitions

Step	Language	Word	Meaning
1	Czech	-o-	—
2	Old Czech	-o-	—

hluchoněmý — Etymology, Origin & Word History | Etymology Explorer