prevent

verb

pre·​vent pri-ˈvent 

prevented; preventing; prevents

transitive verb

1

: to keep from happening or existing

steps to prevent war

2

: to hold or keep back : hinder, stop

—often used with from

3

: to deprive of power or hope of acting or succeeding

4

archaic

a

: to be in readiness for (something, such as an occasion)

b

: to meet or satisfy in advance

c

: to act ahead of

d

: to go or arrive before

intransitive verb

: to interpose an obstacle

preventability

pri-ˌven-tə-ˈbi-lə-tē 

noun

preventable adjective

or less commonly preventible

pri-ˈven-tə-bəl 

preventer noun

Synonyms

• avert
• forestall
• head off
• help
• obviate
• preclude
• stave off

Choose the Right Synonym for prevent

prevent, anticipate, forestall mean to deal with beforehand.

prevent implies taking advance measures against something possible or probable.

measures taken to prevent leaks

anticipate may imply merely getting ahead of another by being a precursor or forerunner or it may imply checking another's intention by acting first.

anticipated the question by making a statement

forestall implies a getting ahead so as to stop or interrupt something in its course.

hoped to forestall the sale

Examples of prevent in a Sentence

Seatbelts in cars often prevent serious injuries.

Can exercise and a healthy diet prevent heart disease?

The accident could have been prevented.

He grabbed my arm to prevent me from falling.

Bad weather prevented us from leaving.

How are you going to prevent him from finding out about the party?

Recent Examples on the Web

Such defenses include profiling victims before an attack is mounted, and can even provide an escape path to a benign alternative to prevent the threat being flagged. —Zak Doffman, Forbes.com, 6 Apr. 2025

Rather than address the underlying medical issues that prevent conception, IVF acts as a Band-Aid solution, artificially fertilizing eggs outside the womb in a laboratory. —John Oertle, National Review, 6 Apr. 2025

While measles is highly contagious, a vaccine against the disease was developed in the 1960s and is 97% effective at preventing an infection. —Joseph Wilkinson, New York Daily News, 6 Apr. 2025

It was credited with helping prevent another riot in 1993, as racial tensions re-emerged following the second trial of police who beat Rodney King in California. —Scott MacFarlane, CBS News, 6 Apr. 2025

Word History

Etymology

Middle English, to anticipate, from Latin praeventus, past participle of praevenire to come before, anticipate, forestall, from prae- + venire to come — more at come

First Known Use

15th century, in the meaning defined at sense 4c

Rhymes for prevent

• accent
• advent
• ascent
• assent
• augment
• cement
• consent
• dement
• descent
• detent
• dissent
• event

Kids Definition

prevent

verb

pre·​vent pri-ˈvent 

1

: to keep from happening

prevent accidents

2

: to hold or keep back : hinder, stop

bad weather prevented us from leaving

preventable adjective

also preventible

-ə-bəl