To avert means to prevent something bad from happening or to turn away from something. When a quick-thinking driver averts an accident by swerving at just the right moment, they've stopped a collision before it could occur. When a teacher averts a classroom argument by changing the subject, she's keeping a small disagreement from becoming a bigger problem.

The word also means to turn your eyes or attention away from something. You might avert your gaze during a scary movie scene. This physical turning away often happens instinctively when we see something uncomfortable or disturbing.

Notice that avert usually involves action taken just in time. A disaster averted is one that almost happened but didn't, thanks to someone's quick thinking or intervention. A diplomat might avert a war through skillful negotiation. A student might avert embarrassment by catching a mistake before turning in an assignment. The word carries a sense of relief: something unwanted was heading your way, but you managed to stop it or look away before it arrived.