Agnes is a feminine given name derived from the Greek Ἁγνή Hagnḗ, meaning 'pure' or 'holy'. The name passed to Italian as Agnese, to French as Agnès, to Portuguese as Inês, and to Spanish as Inés. It is also written as "Agness". The Greek name descends from the Proto-Indo-European *h₁yaǵ-, meaning 'to sacrifice; to worship', from which also the Vedic term yajña originates. The name is mostly used in Greece and in countries that speak Germanic languages. It was the name of a popular Christian saint, Agnes of Rome, a fact which encouraged its wide use.
https://en.wikipedia.org/wiki/Agnes_(name)