inexpressible; indescribable; beyond words
She was not conventionally beautiful, and yet she did have some kind of ineffable beauty that men found fascinating.
in (not)#e ex (out)#fari (to speak) (Latin)
in+ef+ fable. fable means story. story can be told. in-fable means something which can not be uttered such as the name of Lord Voldemort (from Harry Potter). IN+ F (eff) + able--You cannot utter the letter F*** everywhere. There are places where it is unutterable. :)