An article at YourDictionary.com, titled "
How Many Words are in English?" reads in part[
It is true that English borrows recklessly from virtually every language on earth. In fact, "borrow" may be too weak in speaking of English; we should say that English aggressively mugs other languages for their lexical treasure
This can make the construction of plurals interesting.
Take octopus, which is pluralized in English as either octopi (in deference to the fact the word entered English from New Latin) or octopuses (using the English-standard pluralization rule).
However, octopus is actually a New Latin import word from Greek. The word is constructed of a pair of Greek words, okto (eight) plus pous (foot). And pous in Greek takes the plural poda. So if you use the "origin language" pluralization rule, the plural of octopus should be octopoda. Which in a way it is -- the Order which contains all octopods and devilfish is called "Octopoda".