Everyone knows where the labyrinth was. Nobody knows what its name means.
Etymonline says the English word comes from Latin labyrinthus, from Greek labyrinthos. In Greek it meant a maze or a large building with intricate passages, and especially the structure Daedalus built near Knossos in Crete to hold the Minotaur. The origin is unknown, and the entry says it is likely from a pre-Greek language.
The best-known guess ties it to labrys, a word the entry gives as Lydian for a double-edged axe that symbolized royal power. That would make the Minoan palace a "palace of the double axe." Wikipedia adds that many scholars, including Arthur Evans, favored it, and that the double axe was an important sacred symbol in ancient Crete.
It is only a guess. Etymonline cites the linguist Beekes, who calls the axe theory speculative and instead compares laura, a pre-Greek word for a narrow passage. Wikipedia adds that a Linear B tablet from Knossos, usually read as "mistress of the labyrinth," is itself disputed. Some scholars read it differently, with no certain link to the axe.
The English record is also a little untidy. Etymonline gives a Latinized form, laborintus, in the late 14th century and "laberynthe" around 1400.
After that the meaning spread:
- the figurative sense of a confusing situation dates to the 1540s
- the inner-ear structure took the name in the 1690s
So the word for a mythical prison for a monster ended up naming a part of your own ear. The story of where it first came from is still open.