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

The team further enhanced performance by modifying the SMP’s chemical composition and reinforcing it with carbon fibers to improve stiffness and durability. —Jijo Malayil, Interesting Engineering, 26 Mar. 2026

Together, these works reinforce The Aurora Highlands' vision of making public art a central part of daily community life while helping position Aurora as a destination for world-class art. —Brian Sherrod, CBS News, 26 Mar. 2026

OpenAI is battling more than a dozen different death and harm suits, including one centered on a tragic murder-suicide allegedly spurred by ChatGPT reinforcing an unstable man’s paranoid delusions. —Maggie Harrison Dupré, Futurism, 26 Mar. 2026

YouTube invited 30 of its creators to the NewFront to reinforce the message of the presentation, capping things off with a music performance by sibling duo Lawrence. —Dade Hayes, Deadline, 26 Mar. 2026

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