For once, we have an obvious etymology! It is nonetheless interesting: today we explore the word urchin, which entered English in the early fourteenth century and describes those annoyingly spiky sea creatures. It is from yrichon, which was an old term for "hedgehog" (so named because it's a similarly spiky bother), from Old Northern French irichon, from Old French herichun, from Vulgar Latin hericionem, and finally from Latin ericius. This was a series of unsurprising developments, which as a whole trace to Proto-Indo-European gher, meaning "to bristle", again because of the spiky correlation. What is not as connected to sharp stuff is the later emergence of urchin as meaning "filthy street child". This was adapted by the snobby elite who used the term to emphasize how undesirable poor kids were. Also, in the early atomic bombs, an urchin was a device which helped start the reaction! Yay!
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.