This post lists words derived from words in other languages as a result of folk etymology, a process by which speakers adopt the foreign terms after revising them by using existing elements from their native language.
bumblebee: This word stems from the Middle English word humbul-be, but by association with bombeln, meaning “boom” or “buzz,” the initial sound changed.
caterpillar: The word for a butterfly or moth larva stems from the Old French word catepelose (“hairy cat”); the alteration of the third and fourth syllables to -pillar (from Middle English piller, meaning “plunderer”) may have developed from the notion of its destructive effect on plants.
cockroach: This word is derived from the Spanish term cucaracha and employs two words that, when combined, sound similar to the original word.
cockatoo: This bird’s name is from the Malay word kakatua by way of the Dutch term kaketoe.
crawfish/crayfish: Although these are variations of a name for an aquatic animal, the second syllable in each is not equivalent to the word fish; the entire word, ultimately from a Germanic language, stems from the Anglo-French term creveis by way of the Middle English word crevis and is related to crab (and perhaps to carve).
geoduck: This name for a Pacific Northwest clam, which comes from a local Native American term, has nothing to do with ducks—or with the Latin prefix geo-, meaning “earth”; also, the spelling of the first two syllables is inexplicable, since they are pronounced like gooey.
greyhound: The first syllable of this word does not refer to the dog’s color; it is from the Old English term grieg, referring to a female dog.
lapwing: This word for a species of bird started out as the Old English term hlēapewince (“leap wink”), inspired by the bird’s flapping mode of flight.
mandrill: This word for a type of baboon derived from attempts of English speakers to pronounce the name of the animal in an African language.
mongoose: The animal’s name stems from mamgusa in Prakrit, an Indic language. (It has nothing to do with geese, so the plural is mongooses.)
muskrat: This animal is a rodent, but its name is not derived from its scent or its kinship with rats; the word from which it derives is of Algonquian origin.
peacock/peahen/peafowl: The first syllable of these words comes from pavo, the Latin (and Spanish) name for it. Peafowl is redundant, while peacock and peahen denote the male and female of the species.
polecat: The first syllable of this name for a mammal in the weasel family (also an alternative name for the polecat’s relative, the skunk) is derived from the French term poul (the base of poultry), from its barnyard depredations.
popinjay: This older term for a parrot, now exclusively applied to an arrogant person, is ultimately from the Arabic word babghā’.
quahog: This word for a type of clam stems from poquauhock, from the Narragansett language, and has no relation to pork.
sockeye: The name for a type of salmon does not refer to its eyes; it originates from an attempt to pronounce a Native American word for the fish.
wheatear: This thrush was originally called a wheatears; that name is a euphemism for “white arse,” a reference to its light-colored rump.
white rhinoceros: White, in the name of this animal, is not a reference to its color; it stems from the Afrikaans adjective weit, meaning “wide,” a description that distinguishes its wide upper lip from the pointed lip of the black rhinoceros.
woodchuck: This alternative name for the groundhog derives from the assignment of two English words whose sounds resemble those of a Cree word.