Meaning of “Christmas” - Learner’s Dictionary

Christmas

noun [ C, U ] uk us /ˈkrɪsməs/

the Christian period of celebration around 25 December, when Christians celebrate the birth of Jesus Christ and people give each other presents, or the day itself:

We're going to my mother's for Christmas.
Merry Christmas!
Christmas dinner
→ See also Father Christmas

(Definition of “Christmas” from the Cambridge Learner’s Dictionary © Cambridge University Press)