Where does “ρηχός” come from?

ρηχός (Greek) comes from Ancient Greek ῥηγός, from Ancient Greek ῥᾶχός.

ρηχός (Greek): shallow

Definitions

Step	Language	Word	Meaning
1	Ancient Greek	ῥηγός	—
2	Ancient Greek	ῥᾶχός	—

ρηχός — Etymology, Origin & Word History | Etymology Explorer