Within a week, Baltimore Mayor Stephanie Rawlings-Blake (D) went from decrying, via Twitter, the handiwork of rioting “thugs,” to apologizing for using the term. “Sometimes,” she said, “my own little anger translator gets the best of me”—a reference to President Obama’s already iconic comedic turn with Comedy Central’s Keegan-Michael Key a week earlier at the White House correspondents’ dinner.

Obama, too, described rioters as “thugs,” but endured milder pushback, and didn’t back down from using the term. But then, he doesn’t have to stand for another election. If anything, the sequence of events that finds two presumably liberal black elected officials characterizing rioters in a black neighborhood as thugs is the kind of thing that gets some people talking about a (wait for it) “post-racial” America.

But here’s the thing—the meaning of “thug” is changing. It always has been (it used to refer to a class of criminals in India) and it still is, just as the meaning of all words changes over time. “Generous” once meant “noble;” “silly” once meant “blessed;” “awful” once meant “awesome.”

I argued earlier this week on NPR that in American English, thug has come to have racial overtones. More specifically, that to designate rioters such as the ones in Baltimore this week as thugs now carries a coded, alternate meaning of: “black person behaving badly.”

And I may appear to have given the impression that I think anytime a non-black person says the very word thug, they are saying “n—–.” But that’s not it, and explaining why helps us understand the general nature of what it means for a word’s meaning to change.

Words sprout meanings like trees sprout branches. Try giving one meaning for “set.” If a child asked you what a “spread” was, think of how many different answers you could give.

In the same way, thug-equals-n-word could be one usage of, but doesn’t encapsulate all, present utterances of the word. Indeed, one can refer to jack-booted thugs with no racial reference intended. We refer to the Islamic State as thugs, and to date, somewhere between hardly any and none of its members hail from black-American inner cities.

We refer to people as “thuggish,” as opposed to thugs, and still have in our heads the dictionary definition of thug as a “ruffian.” Words are like that—when we say “poor Bill,” poor has a different meaning than if we say “Bill is poor.”

Yes, when we use thug in reference to young men in modern America, I maintain that thug has taken on a racialized overtone over the past 25 years. Assorted writers and figures agree; I am hardly alone. The Urban Dictionary has long had several entries assuming this flavor of thug as fact. References to “white thug” on Google almost always carry an implication that white thugs are the unexpected case, or even phonies trying to “be black.”

In the instance of this report of a surfing riot by white guys in Huntington Beach, the comments section tags the perpetrators as buffoons, grommets, wannabes and such. How is it that spontaneous language labels the ruffians here as just ruffians while thug is used so spontaneously when the ruffians are black?

The reason is that Modern American English increasingly has a way of saying “black criminal.” There is no corresponding word that subtly means “Asian-American criminal.” It is reasonable, then, to assume that the word’s purpose is to suggest that criminality and black go together in some way; that it is more reprehensible to be a black criminal than another kind.

To use thug in this context can be interpreted as a kind of slur. Subtle. Subconscious, even. But that doesn’t mean it isn’t real.

But here’s the key point: for better or worse, black Americans’ use of the term has contributed quite a bit to this. It didn’t start, of course, with hip-hop, but hip-hop lyrics and iconography had plenty to do with the perpetuation of a black “thug” archetype starting in the 198o’s. More to the point, the black “thug” image is as much admired as despised. The thug is thought of as exhibiting a healthy resistance to oppression; he is an outlaw hero, hence expressions like “thug life” and “thug love.”

Is it any surprise, then, that people from outside of the culture would start to sense “thug” as having a racialized ring to it, and even feel comfortable recruiting it themselves, albeit with less affection than many black people use it with?

Affection leads to one more point. Because in black culture the “thug” persona is seen as both a ruffian and a revolutionary, its usage by a black person can come from a different place than it does with others. As often as not, the “thug” is someone you know, or once knew. The thug is more immediately human and relatable.

So if Rawlings-Blake calls rioters thugs, I see room for hearing it differently than if—let’s say—Bill O’Reilly had, and I hear the president’s usage of the word in the same way.

Words have many meanings at the same time. As we know from the n-word, one word can be a slur, a term of affection and something in between, depending on who’s using it and how. Thug has become a related, although hardly identical, case.