Where does “senþnaną” come from?

senþnaną (Proto-Germanic) comes from Proto-Indo-European sent-n-, from Proto-Indo-European sent-, from Proto-Indo-European h₁es- — to be.

Ancestry of “senþnaną”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	sent-n-	—
2	Proto-Indo-European	sent-	to head for, to go, to travel; to feel
3	Proto-Indo-European	h₁es-	to be

senþnaną — Etymology, Origin & Word History | Etymology Explorer