What is the origin of the name Passover as the name for the festival ?
In 1530, the English bible translator William Tyndale translated the first five books of the Septuagint (known as either the Torah or Pentateuch), the Greek version of the Hebrew Bible, or Old Testament to Christians, into English. Up until that time, neither the Hebrew Bible in its original Hebrew nor its Greek version, the Septuagint, had been translated into English. The Hebrew Bible used the word Pesach to describe the lamb that was sacrificed on the 14th day of the first Hebrew month while the Septuagint used the Greek word "Pascha". However, Tyndale didn't want to use the Septuagint's Greek word "Pascha" as the name for the lamb that was sacrificed on the 14th day of the first Hebrew month. Since the word Pascha was the equivalent of the word Pesach, and since Pesach was linguistically related to another Hebrew word mentioned in the Hebrew Bible, Pasach, where both Pesach and Pasach were spelled the exact same way in Hebrew but pronounced differently by Jewish tradition, and since Pasach meant either to "skip over (or on)" or to "pass over (or on)", Tyndale connected the meaning of Pasach to the meaning of Pesach and Pascha, and so instead of using the word Pascha, he instead chose the English word Passover to describe the lamb sacrificed on the 14th day of the first Hebrew month. However, he used the name Passover only for the 22 times this lamb was mentioned in the Torah or Pentateuch because the name Passover was correct for the context of the time frame of events in which those 22 references were mentioned. However, when he translated the New Testament from Greek into English in 1525-1526, Tyndale did not use the name Passover to describe the lamb that was sacrificed on the 14th day of the first Hebrew month in the New Testament. Rather, he used the word Easter for the first time in the first English version of the New Testament because people in England in the 16th century associated the spring season with the Easter festival and because the word Easter was correct for the context of the time frame of events in the New Testament.
Subsequent English translations of the New Testament, however, gradually replaced the word Easter with the word Passover until just one mention of the word Easter remains from William Tyndale's original English translation of the New Testament in 1525-1526: in the New Testament in Acts 12:4 . Even so, there are some versions of the New Testament that replace the word Easter in Acts 12:4 with the word Passover, such as the New King James version.