Originally posted by lawcucui:
Christmas = Christ's mass
The word Christ stems from the Middle and Old English word Crist meaning the anointed one, the Lord's Anointed. It is borrowed from the Latin Christus and from the Greek Christos also meaning the anointed one.
The Greek is a translation of Hebrew mashiah meaning anointed of the Lord or Messiah. In the word Christmas, the suffix mas evolves from the Old English word maesse meaning festival, feast day or mass.