Where does “ribi” come from?

ribi (Estonian) comes from Middle Low German ribbe, from Old Saxon ribbi, from Proto-Germanic ribją, from Proto-Indo-European h₁rebʰ- — to cover, to roof; rib.

ribi (Estonian): rib

Definitions

Ancestry of “ribi”, step by step

Step	Language	Word	Meaning
1	Middle Low German	ribbe	rib, strip
2	Old Saxon	ribbi	—
3	Proto-Germanic	ribją	rib; reef, ridge
4	Proto-Indo-European	h₁rebʰ-	to cover, to roof; rib

Every word from Proto-Indo-European h₁rebʰ- →Every word from Proto-Germanic ribją →Every word from Old Saxon ribbi →