IMPOSSIBLE

adj. 1 hopeless, impracticable, inconceivable, unimaginable, unthinkable, unattainable, unsuitable, out of the question, unachievable, unrealizable, unworkable, unresolvable, unsolvable Reading of the cipher is impossible without a key 2 absurd, ludicrous, preposterous, ridiculous, illogical, unworkable, outrageous, farcical, outlandish, crazy, weird Inventors came up with the most impossible designs for aeroplanes