What is the X in X-mas?
masc. proper name, in Old Testament the son of Seth, from Greek Enos, from Hebrew Enosh, literally "man" (cf. nashim "women," Arabic ins "men, people").
man the son of Seth, and grandson of Adam (Gen. 5:6-11; Luke 3:38). He lived nine hundred and five years. In his time "men began to call upon the name of the Lord" (Gen. 4:26), meaning either (1) then began men to call themselves by the name of the Lord (marg.) i.e., to distinguish themselves thereby from idolaters; or (2) then men in some public and earnest way began to call upon the Lord, indicating a time of spiritual revival.