Dances with Ding-Dongs.
Dear Word Detective: Where did the word "dumbbell" come from? My grandma wants to know. -- Darris, via the internet.
Interesting question, and the fact that it came from your grandmother is evidence that we often use such terms for many years before it occurs to us to wonder about their origins. I am assuming, of course, that your grandma's query was sincere and not a veiled snipe at either you or me. Probably not. I should just cut back on the coffee a bit.
"Dumbbell," meaning a stupid or foolish person, is an American invention dating back to the early 20th century, and largely replaced the earlier term "dumbhead," which in turn arose as a literal translation of the German "dummkopf." In English since around A.D. 1000 "dumb" has meant "incapable of speech," and comes ultimately from an Indo-European root word meaning "stupefaction or dizziness." (Interestingly, the same root also gave us "deaf.") The derogatory use of "dumb" in English to mean "slow-witted" or "stupid" is actually fairly recent, dating back only to the 19th century, although the related words in Dutch and German have long carried both the "speechless" and "stupid" connotations. Use of "dumb" in either sense in English is now considered derogatory.
Back in the days when church bells were rung by hand, a good deal of practice was needed to develop the strength and skill to handle the ropes and pulleys of the heavy bells. Apprentice bell-ringers practiced with an apparatus called a "dumb-bell," in which the actual bells were replaced with non-ringing (i.e., silent or "dumb") weights.
In the 18th century, compact versions of these "dumb-bells" became the first popular home-exercise machines. And when handheld weights became popular a bit later, they too came to be known as "dumb-bells," at least partly because the standard method of exercise involved swinging the weights back and forth. Weights mounted on each end of a steel bar later became known as a "bar-bell," any connection to the ringing of church bells by then having been largely forgotten.
The use of "dumbbell" to mean "slow-witted person" almost certainly wouldn't have appeared were it not for the "exercise weight" sense of "dumbbell." To call someone a "dumbbell" was to make a pun on the "dumb," replacing the "silent" sense with the "stupid."
It is, however, possible that the "bell" part of "dumbbell" in the "stupid" sense may also hark back to an old slang use of "bell" to mean "head," making "dumbbell" in this sense a direct echo of "dummkopf" and a rather clever double pun
