Constriction is the act of squeezing or tightening something, making it narrower or smaller. When a boa constrictor wraps around its prey, it applies constriction, tightening its coils each time the animal exhales until it can no longer breathe.

The word appears in many contexts. A doctor might notice constriction in a patient's blood vessels, meaning they've become too narrow for blood to flow properly. Cold weather causes constriction in the tiny blood vessels in your fingers and toes, which is why your hands feel cold and look pale on winter days. Your throat might feel constricted when you're nervous before giving a speech, as if something is squeezing it tight.

People also use constriction to describe anything that limits or restricts. A tight collar creates physical constriction around your neck. Strict rules might feel like a constriction on your freedom to make choices. The feeling of constriction is that sense of being squeezed, compressed, or hemmed in, whether literally by something wrapped around you or figuratively by circumstances that limit what you can do.