Merry Christmas

"Merry Christmas" was a greeting traditionally used during the Christmas season. Alternatives included "happy Christmas" and "season's greetings".

On Christmas Day 2007, Donna Noble wished "Merry Christmas" to the Tenth Doctor before he left Earth. (TV: The Runaway Bride)

The glass avatar version of Clara Oswald wished a "Merry Christmas" to the Twelfth Doctor when she manifested. (TV: Twice Upon a Time)