To prevail means to win out in the end, especially after a struggle or challenge. When you prevail, you succeed despite obstacles, opposition, or difficulty.

In a close basketball game, the team that prevails is the one that wins, often after fighting hard through the final quarter. When a scientist prevails in proving a new theory, she succeeds in convincing others even though many doubted her at first. If you prevail in an argument with your brother about whose turn it is to do dishes, you've won your case, probably with good evidence and persistence.

The word carries a sense of overcoming something. You don't prevail at easy tasks; you prevail when something is genuinely difficult or when someone is working against you. Justice can prevail over injustice. Truth can prevail over lies. Common sense can prevail in a confusing situation.

Prevail can also mean to be widespread or common. If a certain fashion prevails at your school, it means most students are wearing it. If a belief prevails in a community, most people there hold that view.

The word suggests strength and endurance. When you prevail, you've proven yourself capable of staying the course and coming out on top.