No comment.

Dear Word Detective: I’ve been looking all over the internet but can’t seem to find a precise answer to explain the origins of the word “engram.” According to the Church of Scientology, it is a word “discovered” by their founder L. Ron Hubbard. But I could have sworn I’d seen it used in science fiction novels published long before it was ever mentioned in “Dianetics.” I’ve heard it in Doctor Who, Star Trek, Battlestar Galactica, various classic science fiction novels, and pretty much any geek reference I can think of. Not only that, but in many dictionaries, it’s defined as a word used in psychology. If L. Ron Hubbard did invent the word, I don’t know why psychology would be so quick to adopt it, given Hubbard’s well-known hatred of psychology. I would love it if you could explain the true origins of that word so at long last I’ll know for sure whether it’s truly science, or just science fiction! — Ike.

Oh boy, Scientology. I think I’m gonna need a new email address. But I think I can clear up your questions fairly easily. As far as I can tell, L. Ron Hubbard, the founder of Scientology, never claimed to have actually invented the word “engram,” although he did eventually use it to mean something a bit different than what it had theretofore meant.

“Engram” originated as a term in neuropsychology meaning, as the Oxford English Dictionary explains, “a memory-trace; a permanent and heritable physical change in the nerve tissue of the brain, posited to account for the existence of memory.” The term was coined in the early 20th century by Richard Semon, a German biologist, who believed that as memories form they leave actual lasting physical traces or changes in the brain, which are then re-activated in recalling the memory. The word “engram” is taken from the Greek “en” (in) plus “gramma” (letter), giving the sense of something “written into” the brain. Much energy was apparently devoted in the following decades to poking around the brain looking for these “engrams,” but today neuroscientists generally agree that memory is a far more complex and diffuse system than simply things being written into the brain.

Evidently Hubbard, in his “Dianetics the Modern Science of Mental Health” (1950), originally used the word “engram” in the standard neuropsychological sense of “memory,” but later refined the concept to define “engram” specifically as a sort of stored moment of psychic pain which must be uncovered and resolved (in a process Scientology calls “auditing”) in order for the person to live a happy life.

Or maybe raccoons.  I’ll bet they’re good at it.

Dear Word Detective: I was just searching your archives for the origin of “O.K.,” which you handled quite succinctly, and discovered to my amazement that there are no words under “X.” What about “xenophobic” and “xenon”? Does no one care whether or not they are related or where they came from? — John Pearson.

Well, lookie there. Apparently it’s National Neglected Letter Week. We just finished adding a “Z” word to the Word Detective website archives at www.word-detective.com, and now we’re wrestling with “X.” Does this mean we’re done and my career (such as it is) is winding down? Cool. I’ll have more time to devote to farming. Right now, I’m thinking of raising alpacas. Has anyone out there had any luck teaching them to rob banks?

Onward. I, for one, do care deeply whether “xenophobic” and “xenon” are related. Perhaps I’m unduly invested in the idea of an orderly universe, but the thought of millions of completely unrelated words bouncing around chaotically gives me a headache. Fortunately, “xenon” and “xenophobic” are close cousins. By the way, the “x” beginning both words is pronounced as a “z.”

The root of both “xenophobic” and “xenon” is the Greek “xenos,” meaning “strange” or “stranger.” Coupling “xeno” with the (also Greek) “phobia,” meaning “fear,” we get “xenophobia” meaning “fear of strangers” or, more commonly, “fear of or extreme antipathy toward foreigners.” Oddly enough for a word based on ancient Greek elements, “xenophobia” is a relative newcomer to English, only making its first appearance in print in 1909. “Xenophobia” is one of those words which, although neutral in itself, carries a pejorative tone in modern usage and is more often employed in partisan accusations than in civil discourse. The current debates in the US over immigration and foreign trade policy, for instance, have been peppered with accusations of “xenophobia.”

“Xenon,” being an odorless, invisible, inert gas making up a minuscule part of Earth’s atmosphere, is considerably less controversial. Xenon was discovered in 1898 by William Ramsay and Morris Travers, the same guys who had earlier discovered neon and krypton (thus paving the way for both Las Vegas and Superman).

In naming “xenon,” Ramsey and Travers were reflecting the fact that the gas was “strange” in that it was very heavy, as gases go, and possessed some other odd characteristics. Similarly, the name “krypton” is based on the Greek “kryptos,” meaning “hidden,” because it is rare, and “neon” on the Greek “neos,” or “new,” because it was previously unknown. These three gases are, by the way, among the six “noble gases” (“noble” in this case being used in an archaic sense of “stable” or “not reactive”), and the other noble gases (argon, helium, and radon) are also named from Greek roots (respectively, “argos” (idle, inert), “helios” (sun), and “radius” (ray, as radon is formed from the decay of radium).