Where does “tenēre” come from?

tenēre (Latin) comes from Latin tener, from Proto-Indo-European ten- — to stretch, to extend.

Ancestry of “tenēre”, step by step

Step	Language	Word	Meaning
1	Latin	tener	soft, delicate, tender; young, youthful;...
2	Proto-Indo-European	ten-	to stretch, to extend

tenēre — Etymology, Origin & Word History | Etymology Explorer