Infallible means incapable of making mistakes or being wrong. When something is infallible, it works perfectly every single time without error. When someone claims to be infallible, they're saying they never make mistakes, which is a pretty bold claim since everyone messes up sometimes.

You might hear someone say “nobody's infallible” when a trusted expert makes an error. Even the smartest scientists, the most experienced doctors, and the wisest teachers can get things wrong occasionally. That is why scientists repeat experiments, doctors seek second opinions, and teachers double-check their work.

Some people do claim certain things are infallible. In baseball, some fans treat statistics as infallible guides to player performance, though numbers can't capture everything about how someone plays. In religion, some faiths teach that certain teachings or texts are infallible, meaning they contain no errors.

The opposite of infallible is fallible, meaning capable of making mistakes. Recognizing that people are fallible helps them stay humble, double-check their work, and learn from their errors. When someone acts like they're infallible, refusing to admit mistakes, they often end up making bigger ones because they won't listen to corrections.