Where does “wye” come from?

Wye comes from Old English wiga, which derives from Old English wīġ, of uncertain ultimate origin.

wye (English): The name of the Latin-script letter Y; A Y-shaped...

Definitions

Step	Language	Word	Meaning
1	Old English	wæg	wave; water as an open place / means of...
2	Old Norse	Veggr	—
3	Proto-Germanic	wajjuz	wall
4	Proto-Indo-European	wh̥₁yús	—
5	Proto-Indo-European	weh₁y-	to twist, wind, weave, plait; to wrap, enclose,...

wye — Etymology, Origin & Word History | Etymology Explorer