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

V. be unintelligible, require explanation, have a doubtful meaning, pass comprehension, render unintelligible, conceal, darken, confuse, perplex, not understand, lose, lose the clue, miss, not know what to make of, be able to make nothing of, give it up, not be able to account for, not be able to make either head or tail of, be at sea, wonder, see through a glass darkly, not understand one another, play at cross purposes

Adj. 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) 533, 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

Phr. it's greek to me

N. chance, lot, fate, luck, good luck, mascot, speculation, venture, stake, game of chance, mere shot, random shot, blind bargain, leap in the dark, pig in a poke, fluke, potluck, faro bank, flyer*, limit, uncertainty, uncertainty principle, heisenberg's uncertainty principle, drawing lots, sortilegy, sortition|, sortes, sortes virgilianae, rouge et noir, hazard, ante, chuck-a-luck, crack-loo, craps, faro, roulette, pitch and toss, chuck, farthing, cup tossing, heads or tails cross and pile, poker-dice, wager, bet, betting, gambling, the turf, gaming house, gambling house, betting house, bucket shop, gambling joint, totalizator, totalizer, hell, betting ring, dice, dice box, gambler, gamester, man of the turf, adventurer, dicer|

V. chance, stand a chance, toss up, cast lots, draw lots, leave to chance, trust to chance, leave to the chapter of accidents, trust to the chapter of accidents, tempt fortune, chance it, take one's chance, take a shot at it (attempt) 675, run the risk, run the chance, incur the risk, incur the chance, encounter the risk, encounter the chance, stand the hazard of the die, speculate, try one's luck, set on a cast, raffle, put into a lottery, buy a pig in a poke, shuffle the cards, risk, venture, hazard, stake, ante, lay, lay a wager, make a bet, wager, bet, gamble, game, play for, play at chuck farthing

Adj. fortuitous, unintentional, unintended, accidental, not meant, undesigned, purposed, unpremeditated, unforeseen, uncontemplated, never thought of, random, indiscriminate, promiscuous, undirected, aimless, driftless, designless, purposeless, causeless, without purpose, possible, unforeseeable, unpredictable, chancy, risky, speculative, dicey

Adv. randomly, by chance, fortuitously, unpredictably, unforeseeably, casually, unintentionally, unwittingly, en passant, by the way, incidentally, as it may happen, at random, at a venture, at haphazard

Phr. acierta errando, dextro tempore, "fearful concatenation of circumstances", "fortuitous combination of circumstances", le jeu est le fils d'avarice et le pere du desespoir, "the happy combination of fortuitous circumstances", "the fortuitous or casual concourse of atoms", "god does not play dice with the universe"