Apparently the French word for “unicorn” used to be “unicorne”, which makes perfect sense. But it sounded too much like “une icorne”, so they though “icorne” was the name of the animal, and so “the unicorn” was “l’icorne”. Then later they decided that no, “l’icorne” was the whole name of the animal, so “the unicorn” became “la licorne”. The takeaway being that French is a ridiculous language and linguistics is cool