Put him on a treadmill and cut your utility bills in half.

Dear Word Detective: A few days ago my youngest son was in his playroom throwing toys, kicking them around and falling into piles of them. Joyfully! When I asked him to explain this behavior he said simply, “Just causing a ruckus.” Like I should have known, duh. He said he learned the term from his teacher in school that day and thought it was ok to cause one at home since he and his partners in crime couldn’t do it at school. I’m still dizzy from that logic. So where does “ruckus” come from? Does the word “ruck” have anything to do with it? From the dictionary meanings of either word I didn’t get a real connection. — Michael.

Well, there you go. Your son is still in the guileless phase when children see no reason to prevaricate. Enjoy it while it lasts, and just be glad he doesn’t come home and announce, “My teacher says I’m in-cor-rig-ible. What does that mean?” Anyway, eventually you’ll be lucky to get him to admit to anything, no matter how obvious it is (“Did you shave the dog?” “What dog?”).

A “ruckus” is, as your son knows, a disturbance, fuss, uproar or commotion. On the spectrum of, shall we say, “unstructured activities,” a “ruckus” is at the mild end, perhaps a bit more unruly than a “kerfuffle,” but less dramatic than a “brouhaha” and certainly less serious than a “melee.” A “ruckus” is a minor disturbance, full of sound and a little fury, but rarely resulting in serious consequences.

Considering that human beings have been acting up since Friday night cave brawls, “ruckus” is a surprisingly recent arrival, first appearing in the late 19th century. Interestingly, “ruckus” seems to have arisen as a blending of two earlier words, “rumpus” and “ruction.”

“Rumpus” will be familiar to anyone who grew up in the US in the 1950s, because what you call your son’s “playroom” would back then have been called a “rumpus room.” This was a place, often in the basement of a suburban house, where children and teenagers were left more or less to their own devices. The word “rumpus” dates back to the 18th century, and may have arisen as an alteration of “robustious,” meaning “boisterous” (and related to “robust”). Or “rumpus” may have been just someone’s fanciful invention that took hold and spread.

“Ruction” is a bit more recent than “rumpus,” first appearing in the early 19th century, but its origin is even more of a mystery. “Ruction,” meaning a disorderly tumult, may have started out simply as a clipped form of “insurrection.”

Your hunch to look at “ruck” as a root of “ruckus” was sound, but a dead end. There are five separate “rucks” in English, only one of which, a shortened form of “ruckus,” has anything to do with disorderly conduct. The word “rucksack,” meaning a bag or pack carried on one’s back, is taken directly from the German word “rucksack,” based on “rucken” meaning “back.”

Not to mention the landlord who insisted on calling me “Morris Evans.”

Dear Word Detective: I have a British friend who refers to me as “old bean.” Where does “old bean” come from? — Chris.

Hmm. How long has this been going on? I ask only because if someone were routinely addressing me with a term I didn’t understand, I’d be pawing through a dictionary toot sweet. Then again, I understand the tendency to let this sort of thing slide. Back when I was a child and the name “Evan” was exceedingly rare in the US, teachers and other grownups had serious problems getting my name right. They either pronounced it weirdly (usually “Eee-von”) or, on at least one occasion, insisted that I must have misheard my parents and that my name was actually “Kevin.” I gave up arguing after that. Now I answer to anything short of “Lassie.”

“Old bean” is a classic British familiar form of address, roughly equivalent to an American’s greeting of “buddy,” “pal” “friend,” or, at least lately, “dude.” It doesn’t actually mean anything, although to American ears it certainly sounds slightly odd.

Part of what probably strikes Americans as weird about “old bean” is that it doesn’t fit with any of the uses of “bean” with which we are familiar. A “bean” in the literal sense is, of course, the seed of a leguminous plant (or another plant product that resembles one, such as a coffee bean). Beans being perhaps our most humble but infinitely useful food, it’s also not surprising that “bean” has been used in a wide variety of figurative senses for hundreds of years.

One of the earliest instances of bean-as-metaphor, dating back to the 13th century, was “bean” used to mean an item of little value, a sense which lives on in such expressions as “a hill of beans,” “not to know beans” (knowing nothing useful) and “bean counter,” meaning one consumed by meaningless details and thus ignorant of the truly important things.

But beans also served as a symbol of hardship and humiliation. “To give a person beans,” in the early 19th century US, was to punish or deal with them severely, probably as a reference to the unpleasantness of punishment with a diet consisting of only beans. For reasons that are not entirely clear, the use of “old bean” as a form of address seems to have sprung from this sense in the early 20th century. My guess is that it began as a term of mock-commiseration, as if the one addressed were routinely “given beans” or constantly put upon. It is also possible that “old bean” partly invokes the use of “bean” as slang for the human head (and, by extension, a person), which appeared at about the same time in baseball jargon (e.g., “bean ball,” a pitch thrown at the batter’s head) but quickly percolated into general usage.

In any case, “old bean” was actually a common friendly form of address in the US in the 1920s, which is slightly surprising since it is now throughly obsolete over here and regarded as a quintessential (if somewhat corny and affected) Britishism.