A disturbance is something that interrupts normal conditions or creates disorder where things were previously calm or organized. When a loud noise interrupts your concentration while reading, that's a disturbance. When someone talks during a movie and bothers other viewers, they're creating a disturbance.

The word often describes unwanted interruptions. A teacher might ask students not to create a disturbance in the hallway while other classes are working. A “Do Not Disturb” sign on a hotel room door asks people not to create any disturbance by knocking or entering.

In science, a disturbance means something that changes or disrupts a system. A forest fire is a major disturbance to an ecosystem. Dropping a stone into still water creates a disturbance that spreads outward in ripples. Meteorologists track atmospheric disturbances that might develop into storms.

The word can describe both small annoyances and serious problems. A disturbance might be as minor as a flickering light that bothers you while studying, or as serious as a major disruption to public order that requires police attention. When you disturb something, you're the one causing the disturbance. The key idea is that something peaceful, orderly, or focused gets interrupted or thrown off balance.