cryptic
cryptical
dark
deep
enigmatic
enigmatical
impenetrable
indecipherable
inscrutable
lost
missed
mysterious
mystifying
obscure
opaque
paradoxical
puzzling
self-contradictory
unaccountable
unexplainable
unexplained
unfathomable
unintelligible
Greek to one
abstruse
all-comprehensive
all-inclusive
ambiguous
antic
arcane
baffling
beguiling
bewildering
beyond understanding
boundless
countless
endless
eternal
exceptional
exhaustless
extending everywhere
extraordinary
fabulous
fanciful
fantastic
fascinating
fathomless
illimitable
illimited
immeasurable
immense
impossible
inarticulate
incalculable
incognizable
incoherent
inconceivable
incredible
inexhaustible
infinite
infinitely continuous
innumerable
interminable
interminate
limitless
absurd
contradictory
inexplicable
irrational
ludicrous
meaningless
terrify
vague
comprehensible
understandable