Where does “sen” come from?

sen (Norwegian Nynorsk) comes from Old Norse sin, from Proto-Germanic senawō, from Proto-Indo-European snḗh₁wr̥, from Proto-Indo-European (s)neh₁- — to spin (thread), to sew.

sen (Norwegian Nynorsk): sinew, tendon

Definitions

sinew, tendon

Ancestry of “sen”, step by step

sen traces back through two separate lines of ancestry.

via Old Norse sin

Step	Language	Word	Meaning
1	Old Norse	sin	cord, tendon, sinew; nerve
2	Proto-Germanic	senawō	cord, tendon, sinew; nerve
3	Proto-Indo-European	snḗh₁wr̥	tendon, sinew; sinew, tendon
4	Proto-Indo-European	(s)neh₁-	to spin (thread), to sew

via Japanese 銭

Step	Language	Word	Meaning
1	Japanese	銭	hundredth of a yen; one-thousandth of a kan
2	Middle Chinese	錢	—

Every word from Proto-Indo-European (s)neh₁- →Every word from Proto-Indo-European snḗh₁wr̥ →Every word from Proto-Germanic senawō →