When something is unlikely, it probably won't happen, but it still could. An unlikely event has only a small chance of occurring. If you flip a coin ten times, getting heads every single time is unlikely, though not impossible. If dark storm clouds fill the sky, rain is likely, but sunshine is unlikely.

The word helps us think about probability without pretending we can predict the future perfectly. A basketball team that's lost every game this season could still win their next one, but victory seems unlikely. An unlikely hero is someone you wouldn't expect to save the day, like the quiet student who ends up solving the problem that stumped everyone else.

Scientists and weather forecasters use unlikely when they've studied the evidence but can't be completely certain. A meteorologist might say snow is unlikely in July, meaning the conditions make it extremely improbable, though technically not impossible.

The opposite is likely, meaning something probably will happen. Understanding likelihood helps you make good decisions: you might bring an umbrella when rain seems likely, or skip it when rain seems unlikely.