Indigestible means impossible or very difficult for your body to break down and absorb as food. When something is indigestible, your digestive system can't process it the way it handles normal food like bread, vegetables, or chicken.

Some things are naturally indigestible for humans. If you accidentally swallow a small plastic toy piece, it will pass through your body unchanged because your stomach acids and enzymes can't break down plastic. Tree bark, certain tough plant fibers, and other materials just aren't meant to be food for humans, even though some animals can digest them perfectly fine. A termite can digest wood, but you can't.

Other foods might be mostly digestible but contain indigestible parts. Corn kernels have an outer coating that your body can't break down, which is why you sometimes see whole kernels in your poop. The word can also describe food that's extremely hard to digest, like a meal so heavy and rich that it sits uncomfortably in your stomach for hours.

You might hear someone say a complicated explanation was indigestible, meaning it was too dense or confusing to understand, like mental food that's impossible to process. Just as your stomach can't handle certain physical materials, your mind sometimes encounters ideas that are too complex or poorly explained to absorb.