strengthen
Americanverb (used with object)
verb (used without object)
verb
Other Word Forms
Derived Forms
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strengthenernoun
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overstrengthenverb
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restrengthenverb
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unstrengthenedadjective
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unstrengtheningadjective
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strengtheninglyadverb
Inflected Forms
Participles
Conjugated Forms
Present
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strengthensimple
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strengthenssimple
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have strengthenedperfect
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has strengthenedperfect
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am strengtheningprogressive
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are strengtheningprogressive
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is strengtheningprogressive
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have been strengtheningperfect progressive
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has been strengtheningperfect progressive
Past
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strengthenedsimple
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had strengthenedperfect
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was strengtheningprogressive
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were strengtheningprogressive
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had been strengtheningperfect progressive
Future
Etymology
Origin of strengthen
First recorded in 1250–1300, strengthen is from the Middle English word strengthnen. See strength, -en 1
Explanation
To strengthen is to make something stronger! Rarr. You can strengthen your muscles by working out, or strengthen your brain by learning new words. Anytime you strengthen something, you're making it more resistant, vigorous, or tough. Taking vitamins can strengthen your immune system so you don't get sick. Lifting weights will strengthen your muscles. A powerful lock will strengthen a door. On computers, a reliable firewall will strengthen your virus protection. If something is weak, it needs to be strengthened. Congrats! You just strengthened your vocabulary by checking out this definition!
Vocabulary lists containing strengthen
President Obama's second inaugural address
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
As Mexico’s team prepares to take on England on Sunday night, a match that many predict will be the toughest yet for El Tri, authorities nationwide are vowing to strengthen safety protocols.
From Los Angeles Times • Jul. 3, 2026
The United Nations' weather and climate agency said El Nino conditions were forecast to "strengthen rapidly over the coming months, increasing the likelihood of... extreme weather events in many parts of the world."
From Barron's • Jul. 3, 2026
Investors are also weighing Strategy’s announcement Monday that it could sell bitcoin to raise up to $1.25 billion in cash as the crypto-hoarding company attempts to strengthen its balance sheet.
From The Wall Street Journal • Jul. 1, 2026
Sir Keir said there would be "game-changing investment" to strengthen the Armed Forces on land, at sea and in the air.
From BBC • Jun. 29, 2026
He wore weighted shoes to strengthen his wasted leg muscles.
From "Seabiscuit: An American Legend" by Laura Hillenbrand
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.