On the day she became a Jeopardy! millionaire, Amy Schneider revealed to the TV audience that she had for a long time thought "misled" was the past tense form of a verb "misle," and it was only gradually that she realized that it was actually "mis-led."
No doubt many viewers said, "How could a genius like her have gone awry like that!" And then many others said, "Wait — how did you just pronounce 'awry'?"
The truth is Schneider is like most of us in this regard: Everyone who has learned English words by reading has gotten some pronunciations wrong. Usually we're corrected quickly enough by our parents or teachers — "No, it's 'bay-con,' not 'bah-con'" — but sometimes we get well into adolescence or even adulthood without realizing the misapprehension. Every time someone mentions this phenomenon, plenty of highly literate people chime in to tell of their own missteps. There are long and lively threads on Stack Exchange, Quora, and the New York Public Library blog, just to get you started.
And yes, there's a word for this. In fact, there are several. The established term for a word that a person has learned by reading and has not been told how to pronounce is a "book word." But some people also call these mispronunciations "misles" — usually rhyming "misle" with "guys'll" — in honor of "misled." And Judith Wynn Halsted, in her book Some of My Best Friends Are Books, calls it "Calley-ope Syndrome" after another misleading word, "calliope."
It can't be surprising that English speakers, however literate, mispronounce words some of the time. We get spelling wrong at least as often. English is the Winchester House of languages, developed in a variety of strange and inconsistent ways, with many traps and dead ends, some of which are entirely deliberate. If spelling were a game, English would be the final boss level. There are several ways English spelling has peeled apart from pronunciation, and each of them has produced words that, like misled, are often among book words' bedeviling number.
Sometimes confusion comes because we stole (ahem, "borrowed") a word from another language with different spelling practices. When we do that, sometimes we change the pronunciation to match English expectations (we don't say yoghurt, sauna, and ski like "ya-oort," "sow-na," or "shee," as in the original languages), but sometimes we don't, or at least not entirely.
This is why ennui is supposed to be said like "on we" rather than like what it looks like. It's why potpourri has a silent t (for those who observe the convention). It's why we are supposed to say the c in facade as "s" (really, it should be "façade," but that ç is not an English letter!). And it's how we came not to say the s in viscount — though we have changed how we say the i to the English style. We've also shifted the pronunciation of inchoate ("in-co-it") and caveat ("cavvy-at"), adopted and adapted from Latin, towards English sounds ... but not nearly all the way, per how they look to English eyes.
Oops, wrong language
Sometimes we get it wrong because we know the word is from another language, but we guess wrong as to which language it's from. That's why some people say segue as "seg," French style, rather than "segway" following the Italian origin (of course, some people also say "seg-you" to follow English rules). And sometimes we know what language a word is from, and we get too eager and make it too un-English. That's why cache, which should be said exactly like "cash," sometimes gets said "cash-eh" as though it were "caché" (which, as a noun, it's not; caché is also French, but it's an adjective meaning "hidden").
Gone to Hades
Words borrowed from classical Greek (or based on Greek roots) are special level of Hades. It's not just that they've been converted to a different alphabet — often by way of Latin, which did its own weird things in passing — it's that English has, over the centuries, developed pronunciation standards for classical Greek that sound very little like the Greek originals but even less like normal English.
For example, we're supposed to put the stress on the third-last syllable and pronounce a final e as "ee." That's where the pronunciation of calliope ("ca-lie-o-pee") comes from, along with those of names like Hermione, Penelope, and Persephone, all well known for having misled many readers. It's also given us epitome, hyperbole, and antithesis, all of which are well established in the annals of Calley-Ope Syndrome. And, again, occasionally we've applied the same principles to words taken from completely unrelated languages — for instance, yos se'meti, from an indigenous Californian language, got written as Yosemite, which you'd never guess how to say without being told.
Shifting sands of time
Not all our spelling woes are due to the kleptomania of the English lexicon. English has changed awkwardly since the Angles and Saxons invaded Britain.
Some words were originally spelled as they sound, but over the centuries we shifted how we say them — yet not so much how we spell them. This is what happened to draught ("draft"): that "gh" originally stood for a back-of-the-mouth fricative that you can still hear in Dutch, but that's long gone from English. It's also what happened to waistcoat ("wes-kit") and boatswain ("bo-zun") — as with "cupboard," all their original sounds are still possible in English, but we've just ... economized our pronunciations (unless we only know them from books). This has also happened with many names, such as Worcester ("Wis-ter") and Greenwich ("Gren-itch"). Sometimes so many people are misled by the spellings that the more detailed pronunciation is once more taking hold. You may even be among those who say the "t" in often and soften, formerly lost to the mists of time.
Some words have actually had silent letters inserted in them. Why would anyone do that? Not just because they hate people and want to see them suffer (though that might have been part of it). No, they wanted words to show where they come from — as in, way back in Latin, not just in the French they passed through on the way to us.
This is why "debt" and "subtle" have a silent b and "people" has a silent o: because they trace back to Latin debitum, subtilis, and populus, and certain bookworms wanted everyone to know that. And it's why the word formerly spelled as vitailes (from victualia) became victuals ("vittles"), and the word once written faucon became falcon (thanks, Latin falx!).
But, once again, that spelling has started to win over the pronunciation; the spelling pronunciation of "victuals" is gaining a serious toehold, and just about everyone has been saying the "l" in "falcon" for a long time. Meanwhile, the French words cisme and cedule, when borrowed into English, were eventually respelled as schism and schedule to display their glorious distant Ancient Greek origins, and the result has been absolutely endless arguments about the correct pronunciation of each.
But wait! It gets better — or worse. Sometimes we changed the spelling to match what we thought was the origin, but we were actually wrong about it. The s in "island"? Added on the model of "isle" — but while "isle" comes from Latin insula, "island" is not related: it comes from y, an old word for "island," plus land, which meant then what it means now.
This process has also given us quay, which used to be spelled "key," like the other word it sounds like, but someone noticed the French spell it quai and thought that must be the origin. It's not — the French got the word from the same Germanic source we did and spelled it to please themselves.
And then sometimes we're not even sure where a word came from, but it's there now, like a booby trap, and you'll get caught if you don't look askance at it — oh, by the way, that's "a-skance," not "ask-ance."
Finally, sometimes a word is put together using perfectly reasonable English word formation practices, either from bits that have always been English or from Latin or Greek bits that have been in use in English for centuries, but we've been so thoroughly gaslighted by our spelling that, in our search for something to model the pronunciation on, we guess wrong.
Add bio (from "biographical") to pic (from "picture") and you get biopic, which is supposed to be said "bio-pic" but looks so much like it should rhyme with "myopic." Take the Greek root infra ("below") and add it to good old English red and you get infrared, which to almost any English-speaking brain seems wrongly like it should rhyme with "prepared." Although, a thousand years ago, albeit was obviously al (from "although") plus be plus it, now — under the influence of German borrowings like zeitgeist — many of us would really feel more comfortable if it sounded like "all-bite." And, of course, adding the prefix a- (as in "about" and "around") to wry and the prefix mis- to led ought to lead us naturally to say "a-wry" and "mis-led" for awry and misled. But, well ...
As long as English spelling remains weird and inconsistent — which it will until the end of time — its speakers will continue to be misled by book words and to go awry in their pronunciation. And there will always be those like the former English teacher on Quora who sniffed: "You aresimply [sic] guilty of mispronunciation. If you are not sure of the pronunciaton [sic] of a word, look up a dictionary."
But there will also be those of us who will smile sympathetically and say, as people on Twitter have, "Never make fun of someone if they mispronounce a word. It means they learned it by reading." And let none look askance.