THESAURUS
unknowable
Greek to one, able, ambiguous, arcane, beyond understanding, cabalistic, enigmatic, impenetrable, inarticulate, incalculable, incognizable, incoherent, incomprehensible, inscrutable, mysterious, mystic, numinous, past comprehension, puzzling, rambling, sealed, strange, unapparent, unapprehended, unascertained, unbeknown, uncharted, unclassified, unconnected, undisclosed, undiscoverable, undiscovered, undivulged, unexplained, unexplored, unexposed, unfamiliar, unfathomable, unfathomed, ungraspable, unguessed, unheard, unheard-of, unidentified, unimaginable, unintelligible, uninvestigated, unknown, unperceived, unplumbed, unrevealed, unsearchable, unsuspected, untouched, virgin
ROGET THESAURUS
unknowable
Unintelligibility
N
unintelligibility, incomprehensibility, imperspicuity, inconceivableness, vagueness, obscurity, ambiguity, doubtful meaning, uncertainty, perplexity, spinosity, obscurum per obscurius, mystification, latency, transcendentalism, paradox, oxymoron, riddle, enigma, puzzle, diagnus vindice nodus, sealed book, steganography, freemasonry, pons asinorum, asses' bridge, high Dutch, Greek, Hebrew, jargon, unintelligible, unaccountable, undecipherable, undiscoverable,
unknowable, unfathomable, incognizable, inexplicable, inscrutable, inapprehensible, incomprehensible, insolvable, insoluble, impenetrable, illegible, as Greek to one, unexplained, paradoxical, enigmatic, enigmatical, puzzling (secret), indecipherable, obscure, dark, muddy, clear as mud, seen through a mist, dim, nebulous, shrouded in mystery, opaque, dense, undiscernible, misty, hidden, latent, indefinite, garbled, perplexed, undetermined, vague, loose, ambiguous, mysterious, mystic, mystical, acroamatic, acroamatical, metempirical, transcendental, occult, recondite, abstruse, crabbed, inconceivable, inconceptible, searchless, above comprehension, beyond comprehension, past comprehension, beyond one's depth, unconceived, inexpressible, undefinable, incommunicable, unpredictable, unforeseeable, it's Greek to me.