名詞 christmas:

1. period extending from Dec. 24 to Jan. 6
   同義詞：Christmastide, Christmastime, Yule, Yuletide, Noel
2. a Christian holiday celebrating the birth of Christ; a quarter day in England, Wales, and Ireland
   同義詞：Christmas Day, Xmas, Dec 25

動詞 christmas:

1. spend Christmas

1. Parliament won't be in session again until after Christmas.
   國會將等到圣誕節(jié)后才再進入會期。
2. They decorated the Christmas tree with tinsel.
   他們用亮金屬片裝飾圣誕樹。
3. Christmas is a time of mirth, especially for children.
   圣誕節(jié)是個快樂的日子，尤其是對孩子們。
4. We went to the church to celebrate Christmas Eve.
   我們?nèi)ソ烫脩c祝圣誕前夕。
5. Christmas revels with feasting and dancing were common in England.
   圣誕節(jié)盛宴歌舞的狂歡在英國是很常見的。
6. Christmas commemorates the birth of Christ.
   圣誕節(jié)是為了紀念耶酥的誕生。
7. We usually sing carols at Christmas.
   圣誕節(jié)時，我們一般會唱頌歌。
8. Merry Christmas!
   圣誕快樂！

Christ.mas

n.（名詞）
A Christian feast commemorating the birth of Jesus.
圣誕節(jié)：紀念耶穌誕生的基督教節(jié)日
December 25, the day on which this feast is celebrated.
十二月二十五日，慶祝圣誕節(jié)的日子
Christmastide.
圣誕節(jié)節(jié)期

來源：
Middle English Cristemas
中古英語 Cristemas
from Old English Crostes môsse [Christ`s festival]
源自 古英語 Crostes môsse [基督的節(jié)日]
Crost [Christ] * see Christ
Crost [基督] *參見 Christ
môsse [festival] * see Mass
môsse [節(jié)日] *參見 Mass

【引伸】
Christ.massy 或
Christ.masy
adj.（形容詞）