Where does “phi” come from?

phi (Latin) comes from Ancient Greek φεῖ — phi, the name for the twenty-second letter Φ, φ...

Ancestry of “phi”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	φεῖ	phi, the name for the twenty-second letter Φ, φ...

phi — Etymology, Origin & Word History | Etymology Explorer