To be labyrinthine is to have the properties of a labyrinth.

The labyrinth has number properties:

1. it appeared in Greek mythology
2. a half-man half-bull monster called the Minotaur guarded the golden fleece by violently attacking anyone it found in the labyrinth
3. the labyrinth was a maze of twisty passages all alike.
4. Hercules (or perhaps Theseus), the super hero(s) of Greek mythology, wrestled and bested the Minotaur, driving it from the labyrinth

Generally labyrinthine refers to the third property of labyrinths, vis ``she has a labyrinthine mind'' means that a woman's train of thought is hard to follow not that she has a half-man half-bull monster hidden away in there.

Sources

http://www.perseus.tufts.edu/Herakles/bull.html
which is in direct conflict with
http://www.dilos.com/region/crete/labyrin.html

Lab`y*rin"thine (?), a.

Pertaining to, or like, a labyrinth; labyrinthal.

 

© Webster 1913.