When something degenerates, it declines from a better state to a worse one, breaking down or losing quality over time. A peaceful protest might degenerate into a riot. A friendly argument might degenerate into name-calling. An abandoned building degenerates as weather and time take their toll.

The word often describes gradual decay. A conversation that starts out thoughtful can degenerate into silliness. A civilization at its peak might slowly degenerate over centuries. Your handwriting might degenerate to a scrawl when you're tired and writing too fast.

As a noun, a degenerate refers to someone whose anti-social behavior has declined to an unacceptable level, though this usage sounds harsh and old-fashioned. As an adjective, degenerate can describe this kind of unacceptable behavior, as well as certain kinds of mathematical situations where normal assumptions no longer apply.