Chronic describes something that lasts for a long time or keeps happening again and again. When doctors talk about a chronic illness, they mean a health problem that doesn't go away quickly, like asthma or diabetes. These conditions might be manageable, but they stick around for months, years, or even a lifetime, unlike a cold that clears up in a week.

A chronic problem is one that persists. If your neighbor has a chronic habit of leaving his basketball in your driveway, he keeps doing it over and over, not just once or twice. If a city has chronic traffic jams, those jams happen regularly, day after day.

Doctors contrast chronic illnesses with acute ones. An acute illness comes on suddenly and usually resolves quickly, like the flu or a sprained ankle. A chronic condition requires ongoing attention and adaptation. Someone with chronic back pain learns to manage it rather than waiting for it to disappear completely.

You might also hear people use chronic more casually to describe any persistent annoyance or pattern: chronic lateness, chronic messiness, or chronic complaining. In each case, the key idea is the same: it's not a one-time thing, but something that continues over time.