Where does “Agnes” come from?

Agnes is an English feminine name derived from Ancient Greek Ἁγνή, from ἁγνός meaning pure or chaste, ultimately from Proto-Indo-European h₁yaǵ-.

Ancestry of “Agnes”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Ἁγνή	pure, chaste
2	Ancient Greek	ἁγνός	pure, chaste; holy, sacred; purifying
3	Ancient Greek	ἁγνεία	purity, chastity; purification, cleansing
4	Ancient Greek	ᾰ̔γνός	—