Holiday showed up in the sixteenth century, although earlier it existed as haliday. It comes from the Old English haligdaeg, which is a mix of halig, holy and daeg, day. Fun fact of the day, holy (of course) comes from halig, which comes from the Proto Indo European kailo-, whole or uninjured…the origin word for health.
Eggnog obviously is egg + nog, although as just one word it showed up in 1775. Nog showed up about a century earlier meaning a strong type of beer brewed in Norfolk. Funny how they named the drink after it.
You know, like a song. Which I’ve always wondered why it’s called carol and if it’s related to the name. Ha ha, no. Not at all. It showed up in the fourteenth century meaning either a joyful song or to dance in a ring. It’s from the Old French carole/caroler, but before that is unknown. It might be from the Medieval Latin choraula, a dance to the flute, from the classical Latin choraules, flute player or piper, which in turn is from the Greek khoraules, from khoros, or chorus.
Noel showed up in the late fourteenth century as nowel, which I think makes way more sense spelling-wise. It’s a variant of nael, from the classical Latin natalis dies, birthday. Which…yeah, that’s what it’s supposed to be, isn’t it?
Yule comes from the Old English geol/geola, which are other words for Christmas (although geola could refer to a period of time including December and January). It might be related to joy and jolly, but probably not.
That’s it for etymology this year! I’m still posting next week and I’m sure it will be word-related, but it’s probably going to be something different. We’ll see!
Tony Jebson’s page on the Origins of Old English