Well, you know why the word's come up just now, I suppose. But actually, I think the reason it didn't just get buried in the standard Christmas greeting is that some friends gave me a Christmas card with their very photogenic kids on it and all it said was "Be Merry". Which I liked. But it did get me to wondering about the word itself. Even though it's not spelled the same way, is there some hint of Mary in the meaning?
No. There is not. According to the Online Etymology Dictionary, the Old English word was myrge, meaning pleasant, agreeable or sweet. It comes from the proto-German *murgijaz, which seems to have something to do with the idea of being short-lasting, apparently in the sense of making the time fly.
In America, the word merry doesn't seem to be much in vogue anymore, with the exception of Christmastime. There is a sense of England lingering in it more than most somehow, perhaps because of being attached to things like Robin Hood and his Merry Men, and the Merry Wives of Windsor.
However, of course there is a word which has merry in it which is very familiar in the U.S. that doesn't bring up English associations.
Yep, merry-go-round. It turns out that Middle English was very expansive in its use of merry, using it to mean (again according to the Online Etymology Dictionary): "pleasant-sounding" (of animal voices), "fine" (of weather), "handsome" (of dress), "pleasant-tasting" (of herbs). It was also a time when it got joined to a lot of other words, merry-go-round being the main one that stuck. But there are others that are equally engaging: "merry-go-down" for strong ale, "merry-begot" for an illegitimate birth, "merry-go-sorry" for a mixture of joy and sorrow.
I couldn't get the idea out of my head, though, that Shakespeare had used merry a lot to begin a piece of dialogue. Well, I found a concordance and it turned out that he did use merry a lot, just not in that way. In pages of examples, I only found one that supported my sense of it--"Marry, amen." in Twelfth Night. And it's not clear if that's an example of what I was thinking of. So I was about to give up and accept that I was imagining things when I suddenly realized that maybe he hadn't spelled it that way. Checking the same concordance, it turns out that he uses marry in the way I mean frequently. "Marry, that's a bountiful answer that fits all questions." (Twelfth Night). "Marry, hang you!" (All's Well That Ends Well). This marry means something like "I agree", or "indeed", or "well", and as I suspected, related to Mary. Originally it was a sort of euphemistic oath based on the corruption of her name. So I was right, but I had the wrong merry.
Marry, have a jolly old Christmas, will you?
And if the Nativity's not your thing, you can still have a nice old merry-go-down anyway.