PREVA'IL, verb intransitive [Latin proevaleo; proe, before, and valeo, to be strong or well. Valeo seems to be from the same root as the Eng. well. The primary sense is to stretch or strain forward, to advance.]

1. To overcome; to gain the victory or superiority; to gain the advantage.

When Moses held up his hand, Israel prevailed; when he let down his hand, Amalek prevailed. Exodus 17:11.

With over or against.

David prevailed over the Philistine with a sling and with a stone. 1 Samuel 17:9.

This kingdom could never prevail against the united power of England.

2. To be in force; to have effect; power or influence.

This custom makes the short-sighted bigots and the warier skeptics, as far as ir prevails.

3. To be predominant; to extend over with force or effect. The fever prevailed in a great part of the city.

4. To gain or have predominant influence; to operate with effect. These reasons, arguments or motives ought to prevail with all candid men. In this sense, it is followed by with.

5. To persuade or induce; with on or upon. They prevailed on the president to ratify the treaty. It is also followed by with. They could not prevail with the king to pardon the offender. But on is more common in modern practice.

6. To succeed. The general attempted to take the fort by assault, but did not prevail The most powerful arguments were employed, but they did not prevail