Where does “faisan” come from?

faisan (Old French) comes from Latin phāsiānus, from Ancient Greek φασιανός, from Ancient Greek Φᾱσῐᾱνός, from Ancient Greek Φᾶσῐς — Phasis.

Ancestry of “faisan”, step by step

Step	Language	Word	Meaning
1	Latin	phāsiānus	—
2	Ancient Greek	φασιανός	pheasant
3	Ancient Greek	Φᾱσῐᾱνός	Phasian
4	Ancient Greek	Φᾶσῐς	Phasis