reinforcement

noun

re·​in·​force·​ment ˌrē-ən-ˈfȯrs-mənt 

1

: the action of strengthening or encouraging something : the state of being reinforced

2

: something that strengthens or encourages something: such as

a

: an addition of troops, supplies, etc., that augments the strength of an army or other military force

—usually plural

About 8 a.m. Soviet tanks and armored personnel carriers containing reinforcements approached the gorge from the right flank.

—John Barron

b

: something designed to provide additional strength (as in a weak area)

a bridge in need of steel reinforcements

c

: a response to someone's behavior that is intended to make that person more likely to behave that way again

positive/negative reinforcement

3

psychology : the action of causing a subject to learn to give or to increase the frequency of a desired response that in classical conditioning involves the repeated presentation of an unconditioned stimulus (such as the sight of food) paired with a conditioned stimulus (such as the sound of a bell) and that in operant conditioning involves the use of a reward following a correct response or a punishment following an incorrect response

also : the reward, punishment, or unconditioned stimulus used in reinforcement

Synonyms

• brace
• buttress
• mount
• mounting
• prop
• shore
• spur
• stay
• support
• underpinning

Examples of reinforcement in a Sentence

“We're outnumbered! Call for reinforcements!”

We need to prevent enemy reinforcements from reaching the front line.

The bridge is in need of reinforcement.

You should encourage good behavior with positive reinforcement.

Recent Examples on the Web

According to the American Kennel Club (AKC), proper introductions, consistent training and positive reinforcement can help dogs and cats develop a trusting relationship. —Dan Perry, Newsweek, 19 Feb. 2025

North Korean reinforcements haven’t improved Russia’s faltering fortunes in Kursk. —David Axe, Forbes, 18 Feb. 2025

Or a tweet will come on the screen, and suddenly, one of the teams will get a morale boost — or extra troop reinforcements. —Jennifer Vanasco, NPR, 16 Feb. 2025

There are not enough troops to stop an invasion or to be seen by Moscow as provocative, but the concept only works if there is a clear, unbreakable link between the troops on the ground and larger reinforcements committed to fight once the wire is tripped. —Steven Erlanger, New York Times, 11 Feb. 2025

Word History

First Known Use

1602, in the meaning defined at sense 1

Kids Definition

reinforcement

noun

re·​in·​force·​ment ˌrē-ən-ˈfōr-smənt 

-ˈfȯr-

1

: the action of reinforcing : the state of being reinforced

2

: something that reinforces

Medical Definition

reinforcement

noun

re·​in·​force·​ment ˌrē-ən-ˈfōr-smənt, -ˈfȯr- 

: the action of causing a subject (as a student or an experimental animal) to learn to give or to increase the frequency of a desired response that in classical conditioning involves the repeated presentation of an unconditioned stimulus (as the sight of food) paired with a conditioned stimulus (as the sound of a bell) and that in operant conditioning involves the use of a reward following a correct response or a punishment following an incorrect response

also : the reward, punishment, or unconditioned stimulus used in reinforcement compare recruitment sense 1