Where does “ryð” come from?

ryð (Icelandic) comes from Old Norse rustr, from Proto-Germanic rustaz, from Proto-Indo-European rudʰso-, from Proto-Indo-European h₁rewdʰ- — red.

ryð (Icelandic): rust

Definitions

Step	Language	Word	Meaning
1	Old Norse	rustr	—
2	Proto-Germanic	rustaz	rust
3	Proto-Indo-European	rudʰso-	red
4	Proto-Indo-European	h₁rewdʰ-	red

ryð — Etymology, Origin & Word History | Etymology Explorer