Originally a Saxon word (Eostre), denoting a goddess of the Saxons, in honour of whom sacrifices were offered about the time of the Passover. Hence the name came to be given to the festival of the Resurrection of Christ, which occured at the time of the Passover. In the early English versions this word was frequently used as the translation of the Greek pascha (the Passover). When the Authorized Version (1611) was formed, the word "passover" was used in all passages in which this word pascha occurred, except in Act 12:4. In the Revised Version the proper word, "passover," is always used.

Noah Webster's New International Dictionary of the English Language

1. (n.) An annual church festival commemorating Christ's resurrection, and occurring on Sunday, the second day after Good Friday. It corresponds to the pasha or Passover of the Jews, and most nations still give it this name under the various forms of pascha, pasque, paque, or pask.

2. (n.) The day on which the festival is observed; Easter day.

3. (v. i.) To veer to the east; -- said of the wind.