Running across a new word isn't always quite like making a new friend. But at the very least it's like noticing that some interesting-looking new neighbors have moved into the house across the street: Hmm, what are they up to over there?

So it was the other day when meme popped up in an article I was editing. I'd seen it before, surely, but this time I needed to pay it professional heed. The dictionary on my desk (my actual physical desk) did not know the word, but a number of online references did. The American Heritage Dictionary of the English Language, for instance, defined it thus: "A unit of cultural information, such as a cultural practice or idea, that is transmitted verbally or by repeated action from one mind to another."

It was a deliberate coinage, by Richard Dawkins (yes, the author of "The God Delusion"). In his 1976 book, "The Selfish Gene," he wrote about "the soup of human culture," the idea that human beings "inherit" traits from one another by other means than genetics. "We need ... a noun which conveys the idea of a unit of cultural transmission, or a unit of imitation," he said. " 'Mimeme' comes from a suitable Greek root, but I want a monosyllable that sounds a bit like 'gene.' I hope my classicist friends will forgive me if I abbreviate mimeme to meme."

He went on to specify that his new term "should be pronounced to rhyme with 'cream.' "

As coinages go, meme is pretty good. So many new terms for things are awkward polysyllables or initialisms, or trade names that don't transfer well into general conversation. (Remember the ad campaign "There is no such thing as a Xerox"?)

So the idea of a new scientific term in the form of an easy-to-spell monosyllable sets my heart aflutter. For some reason, it makes me think of the composer Arnold Schönberg's observation (in 1951), "There is still a lot of good music waiting to be written in C major."

So far, so good. But the writer of the piece I was reviewing was using meme in a different sense, one defined thus in a recent piece in the Fort Worth Star-Telegram: "A meme is some sort of content – a saying, joke, rumor, video or other communication – that is spread via instant message, e-mail, blog and other methods across the Internet."

Another, more pejorative usage of meme is to be found elsewhere in the blogosphere, however. It reminds us that the word is connected to ideas of mimicry, with its suggestion of lack of independent thinking. In this sense, meme means more or less "a dumb idea that people cling to, even in the face of contrary facts, and keep repeating."

Thus under the headline, "Another Iraq meme bites the dust," one blogger comments how signs of the military success of the Bush administration's "surge" policy in Iraq are confounding those who argue that the war is unwinnable.

Elsewhere along the ideological spectrum, a political blog called "The Horse's Mouth"took on a Heritage Foundation study that purportedly shows that Democrats "now represent the majority of the nation's wealthiest congressional districts." The "Horse's Mouth" headline: "Silly New Wingnut Meme: Democrats Are The 'Party Of The Rich.' "

Meme works as a put-down in contexts like these because it suggests mindless repetition. Ease of transmission seems to be implicit in the idea of meme. Also implicit here is a metaphor of disease – as in the phrase "viral marketing." Not my favorite, to be sure. And the whole concept of the meme, in Dawkins's original sense, is not without controversy either.

So I'm not quite ready to declare meme a new word-friend. But it does look like an interesting new neighbor to keep an eye on.