1. To keep from happening: took steps to prevent the strike.
2. To keep (someone) from doing something; impede: prevented us from winning.
3. Archaic To anticipate or counter in advance.
4. Archaic To come before; precede.
To present an obstacle: There will be a picnic if nothing prevents.
[Middle English preventen, to anticipate, from Latin praevenre, praevent- : prae-, pre- + venre, to come; see gw- in Indo-European roots.]
pre·venta·bili·ty, pre·venti·bili·ty n.
pre·venta·ble, pre·venti·ble adj.
Synonyms: prevent, preclude, avert, obviate, forestall These verbs mean to stop or hinder something from happening, especially by advance planning or action. Prevent implies anticipatory counteraction: The surest way to prevent war is not to fear it (John Randolph). To preclude is to exclude the possibility of an event or action: a tranquillity which . . . his wifes presence would have precluded (John Henry Newman). To avert is to ward off something about to happen: The pilots quick thinking averted an accident. Obviate implies that something, such as a difficulty, has been anticipated and disposed of effectively: the objections . . . having . . . been obviated in the preceding chapter (Joseph Butler). Forestall usually suggests anticipatory measures taken to counteract, neutralize, or nullify the effects of something: We installed an alarm system to forestall break-ins.
prevent /prvnt/ v. [T] 1 to stop from happening: He prevented an accident by braking his car just in time.2 to stop s.o. from doing s.t.: The rain prevented me from going.
Thesaurus: prevent1 to avoid | avert, stave off. Ant. to let s.t. happen. 2 to block, preclude | hinder, thwart. Ant. to make s.t. possible.