Definition
Being 'infallible' means you're incapable of making mistakes or being wrong—essentially perfect. It's the opposite of 'fallible,' which means capable of error. It's a high bar, and often used to describe things considered absolutely trustworthy. Think of a mathematical formula that always yields the correct answer. Infallibility implies complete reliability and certainty. It suggests an absence of any possibility of error. Few things in life are truly infallible.