re·​in·​force | \ ˌrē-ən-ˈfȯrs How to pronounce reinforce (audio) \
variants: or less commonly

Definition of reinforce

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

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Other Words from reinforce

reinforceable \ ˌrē-​ən-​ˈfȯr-​sə-​bəl How to pronounce reinforceable (audio) \ adjective

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.
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Recent Examples on the Web

The price of insulin has more than doubled since 2012, U.S. Sen. Richard Blumenthal said during a Hartford press conference Monday, reinforcing the need for a law that will lower drug prices. Shannon Larson,, "With the price of insulin skyrocketing in recent years, Blumenthal pushes legislation to lower drug prices," 1 July 2019 This season there will be lots of them, as Durant’s injury in particular has reinforced the idea that a championship is there for the taking. Nick Talbot,, "Writers’ Roundtable: How is NBA Free Agency going to play out?," 29 June 2019 And because grasping the incongruities requires a store of knowledge and beliefs, shared laughter signals a commonality of worldviews, preferences and convictions, which reinforces social ties and the sense of belonging to the same group. Giovanni Sabato, Scientific American, "What’s So Funny? The Science of Why We Laugh," 26 June 2019 The Arctic’s permafrost is thawing out seven decades before it was expected to, which may reinforce a climatic feedback loop by releasing huge amounts of trapped greenhouse gases. David Meyer, Fortune, "G20 Summit May Sideline Climate Goals to Keep Trump Happy During Trade Talks," 25 June 2019 But the family and many community members felt the judgment reinforced their sense that civil rights violations by officers against black people aren't taken seriously. Erin Donaghue, CBS News, "Angry South Bend residents blasted Pete Buttigieg at a town hall. Here is why," 24 June 2019 The very costs Trump decries are what has kept the world at peace since World War II: reinforcing trade, security, commercial and cultural ties. Jeffrey A. Engel, Twin Cities, "Jeffrey Engel: The lesson of D-Day for Americans today," 6 June 2019 Ceramides, like those contained in Dr. Brandt Xtend Your Youth Face Cream, are a smart way to fight dehydration caused by sunburn while reinforcing the skin's barrier function. Kari Molvar, Vogue, "The Best Sunburn Remedies, From Soothing Balms to LED Treatments," 23 May 2019 Macedonia has found that learners who reinforce new words by performing semantically related gestures engage their motor regions and improve recall. Quanta Magazine, "How the Brain Links Gestures, Perception and Meaning," 25 Mar. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reinforce.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of reinforce

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

History and Etymology for reinforce

re- + inforce, alteration of enforce

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Statistics for reinforce

Last Updated

14 Jul 2019

Look-up Popularity

Time Traveler for reinforce

The first known use of reinforce was in the 15th century

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More Definitions for reinforce



English Language Learners Definition of reinforce

: to strengthen (a group of people) with new supplies or more people
: to strengthen (something, such as clothing or a building) by adding more material for support
: to encourage or give support to (an idea, behavior, feeling, etc.)


re·​in·​force | \ ˌrē-ən-ˈfȯrs\
reinforced; reinforcing

Kids Definition of reinforce

1 : to strengthen with new supplies or more people Another squad reinforced the troops.
2 : to strengthen by adding more material for support The wall needs to be reinforced.


transitive verb
re·​in·​force | \ ˌrē-ən-ˈfō(ə)rs, -ˈfȯ(ə)rs How to pronounce reinforce (audio) \
reinforced; reinforcing

Medical Definition of reinforce

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

Other Words from reinforce

reinforceable \ -​ə-​bəl How to pronounce reinforceable (audio) \ adjective

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Comments on reinforce

What made you want to look up reinforce? Please tell us where you read or heard it (including the quote, if possible).


to form ideas or theories about something

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