weak·​en | \ˈwē-kən \
weakened; weakening\ ˈwēk-​niŋ , ˈwē-​kə-​ \

Definition of weaken 

transitive verb

1 : to make weak : lessen the strength of

2 : to reduce in intensity or effectiveness

intransitive verb

: to become weak

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Other Words from weaken

weakener \ ˈwēk-​nər , ˈwē-​kə-​ \ noun

Choose the Right Synonym for weaken

weaken, enfeeble, debilitate, undermine, sap, cripple, disable mean to lose or cause to lose strength or vigor. weaken may imply loss of physical strength, health, soundness, or stability or of quality, intensity, or effective power. a disease that weakens the body's defenses enfeeble implies a condition of marked weakness and helplessness. enfeebled by starvation debilitate suggests a less marked or more temporary impairment of strength or vitality. the debilitating effects of surgery undermine and sap suggest a weakening by something working surreptitiously and insidiously. a poor diet undermines your health drugs had sapped his ability to think cripple implies causing a serious loss of functioning power through damaging or removing an essential part or element. crippled by arthritis disable suggests bringing about impairment or limitation in a physical or mental ability. disabled by an injury sustained at work

Examples of weaken in a Sentence

The disease weakens the immune system. Some are concerned that the increase in taxes will weaken the economy. The beams had been weakened by water damage. efforts to weaken environmental laws The recent setbacks have not weakened our resolve. These kinds of contradictions weaken your argument. The disease causes the immune system to weaken. The dollar has continued to weaken against the euro. Lower interest rates have weakened the dollar.
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Recent Examples on the Web

With his new term come sweeping new powers under a new constitution that also weakens parliament and removes the post of prime minister. NBC News, "Turkey enters new era with same man in charge after Erdogan election triumph," 25 June 2018 Marino withdrew from consideration twice: once citing a family illness and another time after news reports highlighted his role in a bill that weakened the DEA’s enforcement authority. Lev Facher, STAT, "Empty desks, squabbles, inexperienced staff: Exactly who is coordinating White House drug policy?," 18 June 2018 The company’s same-stores-sales growth has weakened after years of steady increases and shareholders have punished Kroger for long-term investments that have weighed on immediate profits. Heather Haddon, WSJ, "Kroger Buys Meal-Kit Company Home Chef in Latest Online Acquisition," 23 May 2018 The high-end of Toronto’s housing market continued to weaken after last year’s boom. Natalie Wong, Bloomberg.com, "Toronto Home Sales Off to Weakest Start Since 2009 Recession," 3 May 2018 Whether the party, weakened after the impeachment and scandals, can mobilize major demonstrations remains to be seen. Time, "Brazil Is Bracing for the Arrest of Former President Luiz Inacio Lula da Silva," 6 Apr. 2018 The government’s appeal of that earlier decision could weaken Comcast’s position in the eyes of Fox’s board as the cable giant battles with Walt Disney Co. DIS 1.62% over Fox. Shalini Ramachandran, WSJ, "Comcast’s Pursuit of Fox Just Got Tougher," 13 July 2018 Last year, a federal judge in Hawaii weakened President Trump’s travel ban by vastly expanding the list of US family relationships that visitors from six Muslim-majority countries could use to get into the country. BostonGlobe.com, "This day in history," 13 July 2018 The decision of the European Parliament weakens the position of all creators. Richard Smirke, Billboard, "Music Industry Bosses Decry 'Missed Opportunity' As European Union Rejects Copyright Bill," 5 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'weaken.' 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 weaken

1530, in the meaning defined at transitive sense 1

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Statistics for weaken

Last Updated

10 Nov 2018

Look-up Popularity

Time Traveler for weaken

The first known use of weaken was in 1530

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More Definitions for weaken



English Language Learners Definition of weaken

: to make (something or someone) weaker, less forceful, less effective, etc.

: to become weaker, less forceful, less effective, etc.

of money : to decrease in value when compared to money from other countries


weak·​en | \ˈwē-kən \
weakened; weakening

Kids Definition of weaken

: to make or become weak or weaker … he didn't want to weaken his message by varying it one bit.— E. L. Konigsburg, Mrs. Basil E. Frankweiler

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Comments on weaken

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


something that serves to warn or remind

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