late Old English Cristes mæsse, from Christ (and retaining the original vowel sound) + mass (n.2).
Written as one word from mid-14c. As a verb from 1590s. Father Christmas first attested in a carol attributed to Richard Smart, Rector of Plymtree (Devon) from 1435-77. Christmas tree in modern sense first attested 1835 in American English, from German Weihnachtsbaum. Christmas cards first designed 1843, popular by 1860s. Christmas Eve is Middle English Cristenmesse Even (c.1300).
A festival commemorating the birth of Jesus, traditionally celebrated on December 25 by most Western Christianchurches. Although dating to probably as early as a.d. 200, the feast of Christmas did not become widespread until the Middle Ages. Today, Christmas is largely secularized and dominated by gifts, decorated trees, and a jolly Santa Claus.