You say conundra, I say conundrums
So, randomly, I decided to look up the plural of conundrum today, and, as this illuminating discussion points out, "conundrum" isn't definitively Latin in origin. I particularly like the correction of the snob who insists that 'octopuses' is wrong:
I hope that Philip Moreland says octopodes not octopi, given that octopus is 3rd declension Greek not 2nd declension Latin. Actually I am sure he does, but for anyone to whom this is news, the word octopodes has four syllables.