A lovely map from i100 of the ways different languages say the word that means "Easter".
You will notice that all the countries around the Mediterranean - the place where Easter was first celebrated, use a word that approximates to "Pascha" - coming from "Passover".
You may also be aware that the earliest celebrations of the feast were in the Mediterranean world, and no later than the 2nd century.
You will note that as the English used the word "Lent" from Anglo-Saxon - which was a month name meaning "Opening up" - so they used the word "Easter" - which was also a month name.
There is only one logical conclusion.
The early Church adopted a pagan festival from Germany. They then completely removed all clues that it was pagan by attaching it to a fictitious story about a man being executed - and unexpectedly rising from the dead. They further removed its pagan clues by changing its name from that of a pagan goddess to that of a Jewish festival that fell at the same time.
They then further covered things up by decreeing that nobody was to mention Eostre's hare / rabbit for 1,000 years. They kept the eggs, though. Because once they'd kept quiet about the rabbit they knew nobody would guess where the eggs came from.
And that is how a totally pagan feast, with a totally pagan timing, became the central feast of the Christian faith. Christians. eh? They'll believe anything.