The only constant in language, as in life, is change. That’s an unsettling reality for many people, since language consists of stipulated meanings — rules agreed on by society at large. When some start flouting those rules for what seems like no good reason, others will be confused and annoyed. That, too, is constant because almost all change brings some discomfort.

When it comes to word meanings, there are four major types of change: functional shift (changing a word’s usual part of speech), broadening the sense, narrowing the sense, and overthrowing the traditional sense altogether.

Functional Shift When Americans started using contact as a verb in the 1920s, there was an outcry. Soon after Theodore Dreiser used it that way in 1925, The Spectator editorialized: “Dreiser should not be allowed to corrupt his language.” A 1933 piece in Harper’s Magazine called it an abomination, adding: “We trust it will still be considered so when the 2000th issue of Harper’s is printed.”

That hopeful prognostication came to naught. The verb proved useful in place of get in touch with. The original suggested replacements — consult with and meet — just don’t work when you want to say, “Contact me next week.” The word is a “hypernym” (a general umbrella term) for a whole series of possible specifics (call, write, come by, send a telegram to, and now email and text and even Zoom). Today almost nobody even realizes that there was once a controversy about the term.

The same can’t be said of impact as a verb. Formerly, the verb use was largely just implied by the adjectival form in the phrase impacted wisdom teeth. But in recent years it has come to be used synonymously with affect in the sense “to have an effect on.” Traceable to the 1940s, this usage didn’t become widespread until the 1970s. From that time until about 2010, it was widely disparaged by those keen on linguistic traditionalism. How will this impact our planning? Today one hears this kind of sentence several times an hour on TV news programs. It’s ubiquitous and hence less objectionable as time goes by.

Why did the noun-to-verb shift take place? People have long struggled with whether to use effect (normally a noun, but also a verb meaning “to bring about”) or affect (usually meaning “to influence”). So people started choosing impact, and the word spread quickly. Although some sticklers still object to this functional shift, impact seems destined to follow the course of contact, with any controversy soon forgotten.

Specialization and Generalization: Narrowing and Broadening

Words often lose breadth over time. Instances in linguistic history are legion. Meat once meant food generally, not just the flesh of an animal to be eaten. Disease once meant discomfort of any kind. Affection once meant feeling of any kind. Tyrant meant simply king or absolute ruler.

This specialization typically occurs so gradually that nobody minds if a genus term comes to denote just a species within that genus.

But the reverse process of generalization often causes anxiety. When a word is ex­tended to cover things once excluded, people may feel that the rules of language are being violated.

The word anxious is a good example. It formerly corresponded closely to the noun anxiety; it meant “nervous, worried, fretful.” As early as the 1500s, though, anxious was also being used in reference to only a certain kind of concern for something: It had come to mean “eager, keen.” Over time, that sense may even have become predominant. Perhaps the only reason some people still occasionally object to the eager sense is the doggedly different meaning of anxiety.

Words once thought to be irretrievably narrow in meaning still elicit objections when they’re used more broadly. Enormity (“monstrous wickedness” since the 1400s), fulsome (“excessive to the point of being offensive” since the early 1600s), and reticent (“reluctant to talk, taciturn” since the early 1800s) are now often used neutrally in reference, respectively, to size, fullness, and disinclination. Sticklers object. As recently as the 2010s, the late John Simon, a language critic as well as a theater critic, was calling such things “illiteracies.”

Reversals in Meaning Nothing bothers the linguistic traditionalist more than the application of a word in a sense entirely different from its established one. Think of disinterested (formerly just “impartial,” but now often “bored”), fortuitous (formerly just “occurring by chance,” but now often “fortunate”), and transpire (formerly “to come to light,” but now usually a fancy equivalent of happen or occur). These can still arouse moderate agitation.

If you really wanted to see fervent denunciations, you could mention the phrase begging the question to the late Justice Antonin Scalia. He insisted, as unrelenting traditionalists do, that the phrase denotes arguing in circles: insisting on the truth of the very thing in dispute (as when somebody argues that everybody admires Jill because she’s so popular). It’s the everyday equivalent of the phrase petitio principii.

But most people don’t even know that use of begging the question. They think the phrase means “inviting the (further) question.” TV commentators typically use the phrase exclusively in that sense.

It’s enough to make you nonplussed. That’s another word that is shifting its meaning diametrically. It has traditionally meant “baffled, flummoxed, mystified.” But in recent years people have started equating it with its near-opposite, unfazed.

It might literally make you hit the ceiling. Well, not literally. Through hyperbole, people are starting to use literally as a mere intensifier of figurative exaggeration. So by overstatement, the word seems to take on the opposite of its actual meaning. Yet nobody would say, “It might make you figuratively hit the ceiling.” You’d literally — quite literally — omit figuratively.

Where Does This Leave Us? Must we simply accept all linguistic change on fatalistic grounds? Absolutely not. Though the language constantly shifts, you’re entitled to grouse and harrumph at newfangled applications of words. Who knows? You might influence your friends and family. Exercise your democratic right to have your say. Just don’t expect fulsome praise.