David Koyzis has a fascinating post on that question. Other languages call the festival of Christ’s resurrection some version of the Aramaic word for “Passover,” namely, “Pascha.” This is a good Biblical term. But the Germans call it “Ostern” and the English call it “Eastern.” The Anglo-Saxon historian the Venerable Bede said that the word derives from “Eostre,” a pagan fertility goddess with rites in the beginning of Spring.
But twentieth-century scholarship has called into question Bede’s interpretation. There is still no general agreement on the origin of the word, but it has been suggested that it may come, not from the name of a goddess, but from eostarun, the Old High German word for the dawn itself. (Our word east obviously has similar origins.) In fact there are some remarkable similarities between the words for resurrection, Easter and dawn in several Indo-European languages. The common meaning underlying these words is a rising of some sort.