I am looking for some examples of words that, possibly due to their non-Latin origin, would have sounded offensive if they went through the English language rules. For example, if a specialty Bohemian medical practice sounded like "rap" then people practicing it would be "rappists," like psychologists who practice psychology. Since that's too close to "rapists," out of respect the word might have been changed to something else, for example "rapsters".
The seed of Guizotia abyssinica used to be known as niger seed. That combination of letters is pronounced differently from the much more common word with a similar spelling, and the difference should be obvious because of the single g. But you'll find it much more commonly listed (e.g. on packaging for bird food) as nyger or nyjer™, a phonetic spelling that dodges any confusion (perhaps not helped by spell checkers not including the original spelling).
Did you know that the original name for Pac-Man was Puck-Man? You'd think it was because he looks like a hockey puck but it actually comes from the Japanese phrase 'Paku-Paku,' which means to flap one's mouth open and closed. They changed it because they thought Puck-Man would be too easy to vandalize, you know, like people could just scratch off the P and turn it into an F or whatever.
Not quite what you are asking, but something similar is found in proper names. The venerable Scottish surname ‘Smellie’ is nowadays often changed to ‘Smillie’ (itself a genuine variant e.g. Wikipedia article on Robert Smillie).
However some Smellies (including my former boss) strongly resist this, as exmplified in this article in the Daily Telegraph.
You still have to be careful with people who spell their surname Smellie. Some of them pronounce it Smillie.
I can think of a word whose pronunciation was changed to make it less offensive: "coney", an archaic word for "rabbit".
I'm told by a former professor and other sources that it originally rhymed with "honey", but was changed to rhyme with "boney" because it sounded too much like a slang word for "cunt".
As per the question's example of change in spelling and word (i.e. "rappists" to "rapsters"), there are numerous words that have changed to a gender-neutral form, often to make them less patriarchal. For example:
- Fireman → Firefighter
- Policeman → Police officer
- Chairman → Chair
- He or She → They (as a singular)
- Woman → Womyn (not exactly in regular usage)
In the case of the first three examples, Dictionary.com says
The use of -man as the last element in compounds referring to a person of either sex who performs some function… has declined a great deal in recent years
Google ngrams depicts the increase in usage of firefighter in recent years.
And police officer.
Do proper nouns count? There's a town in Labrador called Sheshatshiu. Per the Wikipedia page on the settlement, this would have traditionally been spelled differently (the trailing 'u' being replaced by a 't'). In Innu-aimun, it would mean "a narrow place in the river", but in English it becomes "she excreted feces".
One proper-noun example is the Scottish island called Rum. According to Wikipedia, https://en.wikipedia.org/wiki/Rùm, "George Bullough changed the spelling to Rhum to avoid the association with the alcoholic drink rum". It was changed back in 1991, with an accent added.
It is thought that the British title "Earl" was used instead of its continental equivalent "Count" because the latter is close to "cunt". This is the opposite of the suggestion in the question: a Germanic word used instead of a Latin word.
From Swearing: A Social History of Foul Language, Oaths and Profanity in English by Geoffrey Hughes, page 20:
It is a likely speculation that the Normal French title Count was abandoned in England in favour of the Germanic Earl ([Anglo-Saxon] eorl, a nobleman, [Old Norse] jarl, a viceroy) precisely because of the uncomfortable phonetic proximity to cunt, which in Middle English could be spelt counte. The Earl/Countess conjugation is uniquely anomalous among English titles in that the partners are drawn from different word-stocks.
The origin of wheatear is:
probably a back-formation from Middle English whit ers "white arse", after the prominent white rump of many species.
I can't provide any evidence that it was intentionally changed for reasons of decency, rather than simply by the natural mutations of language.
darn for damn; Dictionary.com
tame curse word, 1781, American English euphemism for damn, said to have originated in New England when swearing was a punishable offense; if so, its spread was probably influenced by 'tarnal, short for Eternal, as in By the Eternal (God), favorite exclamation of Andrew Jackson, among others. Related: darned (past participle adjective, 1806); darndest (superlative, 1844).
The Oxford English Dictionary says:
Perversion of damn n., in profane use; ‘confound’.
1781 Pennsylvania Jrnl. 20 June In New England prophane swearing..is so far from polite as to be criminal, and many..use..substitutions such as darn it, for d—n it.
The Cambridge Dictionaries Online Blog, titled Gosh Darn it to Heck! says of the 1781 quotation:
(Note the uses of dashes, a convention that we still use; up until about 1700, damn would more likely have been printed in full.)
In Newfoundland kittiwakes are generally called "tickleaces". An older spelling is "tickle-ass" -- apparently they sometimes fly in very close formations. I'm not certain, though, whether the spelling changed to be less offensive or more phonetic. There are many other spellings listed in the Dictionary of Newfoundland English.
Bic, the company known for making pens, lighters, etc., was originally named after its founder, Baron Michel Bich. "Bich" was changed to "Bic" because the former looked like it would be pronounced "bitch."
Another company that changed its name for similar reasons was Jay's Potato Chips, which used to be called Japp's Potato Chips (named after their creator, Leonard Japp, Sr.). It was changed after the attack on Pearl Harbor, when the homophone "Jap" began to have very negative connotations.
It's related because it is about spelling, and how these words change their meaning. I'm talking about website domains, and unfortunate urls.
www.swissbit.ch. (a Swiss penknife company)
Whorepresents.com (who represents.com)
Expertsexchange.com (experts exchange.com)
Penisland.net (pen island.net)
Therapistfinder.com (therapist finder.com)
For the complete list, see 30 Unintentionally Inappropriate Domain Names