Do remember that some people are slow to change. My grandfather insisted on calling jeans 'dungarees' all his life, long after that went out of fashion. Just because a name changed 'officially' doesn't mean everyone changed instantly.
Indeed, and some will rage when a word changes meaning, or when a new word comes into fashion.
I sometimes laugh at my author group. My current WIP is set in 12th century Ireland, and they will occasionally ask if a particular word was used then. None of these words were used then! Modern English wasn't in existence then! At this point, it was still middle English, and still a strong mix of Norman and Anglo-Saxon. However, since my book must be written in modern English, some words may, indeed, jar the reader out of the illusion of medieval Irish life.
It comes up pretty frequently when people want to write stories set in pre-Norman, or even 12th century, England. They want to write it the way people really spoke back then, some say. Um, no they don't, because most modern readers couldn't understand it.
In these cases, the writer actually gets a bit more latitude than someone writing in the 19th (or 17the) century. It's more a matter of figuring out which modern words and phrases are plausible translations for concepts that people had in that much earlier time. For instance, knowledgeable readers might notice if an early or mid 19th century character wears her hair in a "
bun," because that word wasn't used to describe such a hair style then (I think they used words like "knot." But if the book is set in ancient Rome, or even an England before modern English evolved, then it's a plausible translation for whatever term people did use back then.
There was one that they asked about, and I looked it up. The word was actually a word then (can't remember what it was at this point) - but if it threw people out of the story, perhaps I could find a different one... we have many to choose from!
That happens sometimes. There are modern words that most people think are old, and there are older words than most people think are modern.
Things that toss me out are when a pre-20th century character refers to/thinks of "adrenaline." Also, when the word "addiction" is used in a modern, clinical sense (for physical and psychological dependence on a drug). The word does go back to the 1600s, but it meant a penchant or tendency back then. The complexity is that an "addiction" in the original meaning of the word could lead to what we think of as a clinical "addiction" today, and it's likely that people didn't really draw a line or differentiate the two before a modern understanding developed. But having someone in the 19th century, or before, give a 12-steps style pep talk about addiction to a "drunkard" feels just a wee bit out of place.
One type of anachronism I notice are food and livestock ones: turkeys in medieval Europe, or pumpkins, potatoes, or corn (though the word is sometimes used by British writers to refer to wheat, so it can be hard to tell).
Historically inspired fantasy settings are another matter, of course. Since we're suspending disbelief about cultural parallels in unconnected worlds anyway, there's no reason why they couldn't have turkeys and potatoes in a part of their world that vaguely resembles medieval Europe. Unless the element that is present is something that would likely have pushed cultural development really far off that path. Gunpowder-free worlds with ships that greatly resemble 17th and 18th century models that were built (in our world) to accommodate banks of cannons can make me go "Huh?"
