(a.) Not decipherable; incapable of being deciphered, explained, or solved.

Greek to one abstruse all-comprehensive all-inclusive ambiguous antic arcane baffling beguiling bewildering beyond understanding boundless countless cryptic dark deep endless enigmatic eternal exceptional exhaustless extending everywhere extraordinary fabulous fanciful fantastic fascinating illimitable illimited immeasurable immense impenetrable impossible inarticulate incalculable incognizable incoherent inconceivable incredible indecipherable inexhaustible infinite infinitely continuous innumerable inscrutable interminable interminate limitless marvelous measureless miraculous mysterious mystifying no end of numinous obscure occult opaque outlandish passing strange past comprehension perpetual perplexing phenomenal prodigious puzzling rambling rare recondite remarkable sensational shoreless strange striking stupendous sumless termless unaccountable unbelievable unbounded uncircumscribed unconnected undecipherable unexpected unfathomable unheard-of unimaginable unintelligible unique universal unknowable unlimited unmeasurable unmeasured unnumbered unplumbed unprecedented unsearchable untold without bound without end without limit without measure without number wonderful wondrous