What is the X in X-mas?
Old English nan (pron.) "not one, not any," from ne "not" (see no) + an "one" (see one). Cognate with Old Saxon, Middle Low German nen, Old Norse neinn, Middle Dutch, Dutch neen, Old High German, German nein "no," and analogous to Latin non- (see non-). As an adverb from c.1200. As an adjective, since c.1600 reduced to no except in a few archaic phrases, especially before vowels, such as none other, none the worse.