Origin of the word

The word for Christmas in late Old English is Cristes Maesse, the Mass of Christ, first found in 1038, and Cristes-messe, in 1131. In Dutch it is Kerstmis, in Latin Dies Natalis, whence comes the French Noël, and Italian Il natale; in German Weihnachtsfest, from the preceeding sacred vigil. The term Yule is of disputed origin. It is unconnected with any word meaning "wheel". The name in Anglo-Saxon was geol, feast: geola, the name of a month (cf. Icelandic iol a feast in December).

-- THE CATHOLIC ENCYCLOPEDIA