It's probably one of the best known words/expressions in Judaism. I'm sure it's in large part because of Fiddler on the Roof, but it seems that even those with almost no knowledge of Judaism now that "L'Chaim!" is the Jewish version of “Cheers!” And that it means, “To life!”
It turns out that this innocuous little phrase is actually the source of some scholarly debate. I've seen recently some questions about the grammar—that isn't actually a proper phrase. But, there's even more debate about its origins. If you like quirky little explorations of folkways, click on through—it's an interesting, short article.
One aspect of the article which I found interesting, almost as an aside, is that among the several most likely incorrect explanations of the term is one which connected it to potentially poisoned wine.
The opinion asked for was whether the wine might be harmful or even poisoned, as it was in the case of several assassinated monarchs of the Byzantine period — i.e., whether the drinker of it was destined for life or death. Only after the assembled company responded resoundingly ‘L’chaim,’ ‘For life,’ was the wine drunk.So, it was a symbolic way of warding off evil/poison before we drank: to life; not to death!
As the article shows, it's incredibly unlikely that this reflects the actual origin. But it does accurately reflect a Jewish preoccupation with negative explanations for customs of unknown origin. Why do we whisper the line after the Shema*? Because the Romans didn't like the statement, which could have been interpreted as rebellious. Why do we read Haftarah (a reading from the Prophets after the Torah reading)? Because the Romans (there they are again—those dastardly Romans!) outlawed the reading of the Torah, so this was the next best thing.
* Most Reform synagogues don't do this, actually. Ironically, that's because we rejected the original reason for the whispering, except that like the "poisoned wine" theory, it was probably a completely false explanation!
One of my professors (I'm 99% sure that it was Dr. Carole Balin) referred to it as the “Lachrymose Theory of Jewish History.” Everything in Jewish history could be explained as something tear-filled. Everything goes back to something negative, and painful.
Clearly, Jews have had our share of misfortune. In fact, we've had several people's shares. But, we've also had some good times. We've had more than our share of joy, when times are good, too. “L'Chaim” is probably nothing more than a polite way of gathering everyone before a joyous blessing. Sometimes, raising a glass and toasting to life is enough.