Impossible/ɪmˈpɑːsəbl/ Definition 1 of 3Pro Tip 1/3Literal Impossibility Used to state something cannot happen due to laws of nature or limitations. Flying unaided like a bird is impossible for humans. Pro Tip 2/3Hyperbolic Expression Often used to emphasize the difficulty of a task, not always literal. Climbing that mountain in a day seems impossible. Pro Tip 3/3Emphasize Futility Indicates that effort will not change the outcome, suggesting giving up. Arguing with him is impossible; he never listens.