Latinized form of Greek
Κυνθια (Kynthia) which means "woman from Kynthos". This was an epithet of the Greek moon goddess
Artemis, given because Kynthos was the mountain on Delos on which she and her twin brother
Apollo were born. It was not used as a given name until the Renaissance, and it did not become common in the English-speaking world until the 19th century.