IMPROBABILITY, n.
His tale he told with a solemn face And a tender, melancholy grace. Improbable 'twas, no doubt, When you came to think it out, But the fascinated crowd Their deep surprise avowed And all with a single voice averred 'Twas the most amazing thing they'd heard-- All save one who spake never a word, But sat as mum As if deaf and dumb, Serene, indifferent and unstirred. Then all the others turned to him And scrutinized him limb from limb-- Scanned him alive; But he seemed to thrive And tranquiler grow each minute, As if there were nothing in it. "What! what!" cried one, "are you not amazed At what our friend has told?" He raised Soberly then his eyes and gazed In a natural way And proceeded to say, As he crossed his feet on the mantel-shelf: "O no--not at all; I'm a liar myself."
--Ambrose Bierce - The Devil's Dictionary