The word shark has uncertain origins. What we know for sure is that the animal was first brought back to England by John Hawkins, whose crew had dubbed it a "sharke". They provided no source for this word, but there are several theories. The dominant conjecture is to the Yucatan word xoc, which referred to "an ill-defined group of large fish or whales", according to a paper by etymologist Tom Jones. This came from the term hkan xoc through ah kan xoc, which was the morpheme applied to a mythological giant creature. This probably traces to the even earlier phrase chak uuyab xooc, which sort of meant "demon fish", or at least we think so. Both evidence and research at that point and beyond get blurred. This is certainly a viable theory, but there's a wrench (according to Jones): "why is there no trace of [xoc] in Spanish [if it's] from Yucatec?" There should be; the Spanish had much more influence and time in the area than some English explorer. This is why a second theory is proposed: it may be from the German word schurke ("scoundrel"), from Old German scuren. We also mustn't discount the possibility that the crew made up the word. I guess this a quest for linguistics sharks!
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd