Where does “γιατρός” come from?

γιατρός (Byzantine Greek) comes from Ancient Greek ἰατρός, from Ancient Greek ἰάομαι — I cure, I heal; I repair.

Ancestry of “γιατρός”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ἰατρός	physician, surgeon, medical doctor
2	Ancient Greek	ἰάομαι	I cure, I heal; I repair