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
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
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
Bickerstaff occasionally turned to Paul Reed for reinforcements, even benching Duren for Reed for the entirety of the fourth quarter and overtime in Game 5.
—Hunter Patterson, New York Times, 18 May 2026
Techniques such as reinforcement learning from human feedback encourage the model toward preferred responses.
—Sandeep Shilawat, Forbes.com, 15 May 2026
The environment also supports reinforcement learning and imitation learning for AI-powered robotic systems.
—Neetika Walter, Interesting Engineering, 15 May 2026
Use them for training climbing plants and providing reinforcement.
—Rebecca Jones, Southern Living, 14 May 2026
See All Example Sentences for reinforcement
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Hunter Patterson, New York Times, 18 May 2026
Techniques such as reinforcement learning from human feedback encourage the model toward preferred responses.
—Sandeep Shilawat, Forbes.com, 15 May 2026
The environment also supports reinforcement learning and imitation learning for AI-powered robotic systems.
—Neetika Walter, Interesting Engineering, 15 May 2026
Use them for training climbing plants and providing reinforcement.
—Rebecca Jones, Southern Living, 14 May 2026
See All Example Sentences for reinforcement
Cite this Entry
“Reinforcement.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reinforcement. Accessed 21 May. 2026.
Copy CitationKids 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
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