re·​in·​force | \ ˌrē-ən-ˈfȯrs How to pronounce reinforce (audio) \
variants: or less commonly
reinforced also reenforced; reinforcing also reenforcing; reinforces also reenforces

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 While Williamson may indeed be next, Antetokounmpo and the Bucks are now, something that was reinforced Tuesday night at Smoothie King Center. Matt Velazquez, Milwaukee Journal Sentinel, "Bucks 120, Pelicans 108: The first Giannis-Zion clash goes in the veteran's favor," 4 Feb. 2020 The Rio Grande, which marks the boundary between the U.S. and Mexico, is only a stream here, but it’s reinforced with an 18-foot metal wall and multi-lane freeway. National Geographic, "This cheer squad is caught between two worlds—divided by a border," 30 Jan. 2020 The league-worst defense still had everything to prove but had been reinforced up and down the roster, and especially on the back line. Pat Brennan,, "Breaking down FC Cincinnati's roster ahead of the 2020 MLS season," 22 Jan. 2020 The wall along the back side of the graveyard was made of limestone but had been reinforced with steel rebar, some of which was hollow. Colum Mccann, Harper's magazine, "Here and There," 20 Jan. 2020 The material doesn't feel cheap, the zippers and straps can all tuck away, and the handles are all reinforced. Lisa Marie Segarra, Fortune, "Cotopaxi’s Allpa 35L Is a Gadget-Friendly Travel Bag. But Is It Right For You?," 24 Dec. 2019 The fate of the elephants is not known, but the building, whose floors had been reinforced to carry the animals’ heft, has found a new purpose as the home of another weighty cargo. The Economist, "Setting type How the world’s old printing presses are being brought back to life," 18 Dec. 2019 The bins are also weighted, which makes them much harder to move or tip over, and their hinges are reinforced with steel, making them far harder to break open. Heather Knight,, "Toughest job in SF? Tenderloin garbagemen work late at night to clean filthiest streets," 7 Dec. 2019 Lawrence said her concerns were further reinforced after a blistering report from Detroit Auditor General Mark Lockridge determined Duggan's demolition program has been marred by a lack of oversight and administrative failures . Kat Stafford, Detroit Free Press, "Congresswoman wants soil tested on more than 14,000 Detroit blight demolition sites," 14 Nov. 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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Time Traveler for reinforce

Time Traveler

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

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Statistics for reinforce

Last Updated

10 Feb 2020

Cite this Entry

“Reinforce.” Dictionary, Merriam-Webster, Accessed 20 Feb. 2020.

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More Definitions for reinforce


How to pronounce reinforce (audio)

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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