Adianoeta, n. From the Greek for ‘unintelligible’, an expression with both an obvious and another subtle, or even esoteric, meaning; like an allegory or double entendre [via, also, et]. Presumably adianoeta might be translated as, something like, “not through things known” [see].

Amusingly and awesomely, therefore, the word adianoeta is itself an adianoeta, since it implies both that a thing has a secondary esoteric meaning, but also, more subtly, that a thing is unintelligible.