The word stiff describes something that doesn't bend or move easily. A new pair of jeans feels stiff until you've worn them a few times. A door with rusty hinges might be stiff and hard to open. When your muscles feel stiff after sitting too long or sleeping in an awkward position, they're tight and resistant to movement.

People can be stiff too, in different ways. Someone might stand stiffly at attention, holding their body rigid and straight. A person who seems unfriendly or overly formal might be described as stiff, meaning they act uncomfortable or cold rather than relaxed and warm. You might notice this at a party where someone stands awkwardly, not laughing or joining in, seeming stiff and out of place.

The word also appears in phrases like stiff penalty (a harsh punishment), stiff competition (tough opponents), or stiff breeze (a strong, steady wind). In each case, stiff suggests something strong, unyielding, or more intense than expected. When something is described as stiff, whether it's cardboard, a challenge, or someone's manner, the word points to a kind of rigidity or firmness that resists bending or flexibility.