reinforce

verb

re·​in·​force ˌrē-ən-ˈfȯrs 

variants or less commonly reenforce

reinforced also reenforced; reinforcing also reenforcing; reinforces also reenforces

transitive verb

1

: to strengthen by additional assistance, material, or support : make stronger or more pronounced

reinforce levees

reinforce the elbows of a jacket

reinforce ideas

2

: to strengthen or increase by fresh additions

reinforce our troops

were reinforcing their pitching staff

3

: to stimulate (a subject, such as an experimental animal) by reinforcement (see reinforcement sense 3)

also : to encourage (a response) by reinforcement

intransitive verb

: to seek or get reinforcements

reinforceable

ˌrē-ən-ˈfȯr-sə-bəl 

adjective

Synonyms of reinforce

• bolster
• prove
• support

Examples of reinforce in a Sentence

The captain sent out another squad to reinforce the troops.

Our camp is reinforced with supplies flown in by helicopter.

The levees will need to be reinforced.

The bad weather forecast only reinforces our decision to leave early tomorrow.

Some critics say that the movie reinforces negative stereotypes about the military.

We do our best to reinforce good conduct in the classroom.

Recent Examples on the Web

But critics and former employees who spoke with CNN say the AI company has long known of the dangers of the tool’s tendency toward sycophancy – repeatedly reinforcing and encouraging any kind of input – particularly for users who are distressed or mentally ill. —Allison Gordon, CNN Money, 6 Nov. 2025

Military power and financial power reinforced each other, as Britain’s wealth depended on moving cargo, which was a key component of the generational wealth created by trade. —Bojan Stojkovski, Interesting Engineering, 6 Nov. 2025

This initial signal has reinforced his confidence in the framework and motivated him to share it more broadly as a potential resource for others exploring similar paths. —Jason Phillips, USA Today, 6 Nov. 2025

The investment returns behind this progress reinforce Gates’ message. —Alexis Abramson, Fortune, 6 Nov. 2025

Word History

Etymology

re- + inforce, alteration of enforce

First Known Use

15th century, in the meaning defined at transitive sense 1

Rhymes for reinforce

• counterforce
• intercourse
• nonrecourse
• watercourse
• bourse
• coarse
• course
• force
• gorse
• hoarse
• horse
• norse

Kids Definition

reinforce

verb

re·​in·​force ˌrē-ən-ˈfō(ə)rs 

-ˈfȯ(ə)rs

1

: to strengthen by additional assistance, material, or support

reinforce the elbows of a jacket

reinforce the argument with facts

2

: to strengthen or increase by fresh additions

were reinforcing their pitching staff

reinforce our troops

3

: to stimulate (a person or animal) with a reinforcer

also : to increase the frequency of (a response) with a reinforcer

Medical Definition

reinforce

transitive verb

re·​in·​force ˌrē-ən-ˈfō(ə)rs, -ˈfȯ(ə)rs 

reinforced; reinforcing

1

: to strengthen by additional material or support : make stronger

reinforced with vitamins

2

: to stimulate (as an experimental animal or a student) by reinforcement

also : to encourage (a response) by reinforcement

reinforceable

-ə-bəl 

adjective