What is the X in X-mas?
fem. proper name, from Latin Berenice, from Macedonian Greek Berenike (classical Greek Pherenike), literally "bringer of victory," from pherein "to bring" (see infer) + nike "victory." The constellation Berenice's hair is from the story of the pilfered locks of the wife of Ptolemy Euergetes, king of Egypt, c.248 B.C.E., which the queen cut off as an offering to Venus. The constellation features a dim but visible star cluster. But the earliest use of the phrase in astronomy in English was as a name for the star Canopus (1601).