Like it or not, language change is driven by mistakes. If every generation of children perfectly learned what they heard spoken around them, then languages would be exact duplicates of themselves, never changing over the centuries. Clearly, this isn't what happens. As you can see from this list from Vocabulary.com, words have very often been formed by mishearings, inversion of sounds, dropping and adding of sounds, and other all-too-human errors.
a precise rule (or set of rules) specifying how to solve some problem
The Medieval Latin source for this word, algorismus is actually a very bad transliteration of the name of the Arab mathematician who helped introduce higher math to the western world. His surname was al-Khwarizmi which in turn is derived from a place name.
projectiles to be fired from a gun
It is common to misanalyze an article that precedes a word as if it were part of that word. Here the French phrase la munition was misanalyzed so the "a" of the article became part of the word, becoming l'ammunition.
a team representing a college or university
This originated as versity, a short form of university, until the vowel changed for unknown reasons. The cause may be mysterious, but there are numerous examples that are similar, including varmint from vermin, showing the change can go in the opposite direction as well.
Sometimes changes in words are influenced by the (unconscious) sense that words that mean the same should sound similar. That's what linguists think happen with squeeze. There is a form quease, from an Old English root, but linguists figure the initial "s" came about from speakers drawing an analogy between this word and all the other similar words that begin with "squ-": squash and squat most obviously, but also perhaps squirm and squelch.
to walk with a lofty proud gait, often in an attempt to impress others
This word is actually mistake-ridden rendering of the French chassé "gliding step" from a verb that means "to chase". The "sh" and "s" sounds got shuffled from the original.
a localized and violently destructive windstorm occurring over land characterized by a funnel-shaped cloud extending toward the ground
This word comes from Spanish for "thunderstorm," tronada. The inversion of two sounds, in this case the "r" and the "o," is a well-documented process known as metathesis, which is historically also responsible for turning bridd into bird, beorht into bright, and helped turn a luchorpan into a leprechaun, among many others.
come open suddenly and violently, as if from internal pressure
This is another clear instance of metathesis, because the Proto-Germanic root is brest. At some point, the "r" sound jumped ahead in the word and the spelling followed suit.
spice made from the dried fleshy covering of the nutmeg seed
The origin here is from French macis. The "s" was mistaken for a plural marker and dropped, something that has also happened historically to cherry (from Greek kerasos), riddle (from Old English rædels), and recently to kudos, giving kudo.
hand tool for boring holes
The original name of the tool was a nauger, but it was misheard as an auger, so the word lost its inital "n." Linguists call this process "misanalysis."
a group of many islands in a large body of water
The etymology of archipelago seems like it should be from Greek arkhi meaning "chief" and pelagos "sea," suggesting the importance of a sea with so many islands. The problem is that this form never occurs in ancient Greek, and the modern form is actually borrowed from Italian, with the intended meaning being "the Aegean Sea." If that's the case, then the archi- in archipelago is actually a corrupted version of Aigaion, which is how you say "Aegean" in Greek.
To see more words that originated as errors, and to add them to your vocabulary-learning program, see the full list at Vocabulary.com.
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