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

Some suspect certain Democrats in the legislature even hope the investigation will weaken Murphy politically. Andrew Prokop, Vox, "Democrats won 6 more state governments. New Jersey shows what they can do.," 21 Nov. 2018 The eye wall begins to collapse, temporarily weakening the storm. David Grossman, Popular Mechanics, "Florence Makes Landfall, Hundreds Already Need Evacuation," 14 Sep. 2018 However, the hurricane center believes that Beryl will eventually weaken early next week. Stephen Ruiz, OrlandoSentinel.com, "Hurricane Beryl gets stronger, more strengthening expected as it moves west," 6 July 2018 Chris Van Gorder, Scripps Health YES: Longer-term rates haven’t risen much relative to short-term rates, an indication that bond investors believe the economy is weakening. Phillip Molnar, sandiegouniontribune.com, "Is a flattening yield curve a sign of a coming recession?," 6 July 2018 The problem, experts say, is that some of California’s policies sometimes involve other states and could fall short if federal environmental laws are weakened elsewhere. Kurtis Alexander, SFChronicle.com, "Progress on environment could slow on Supreme Court without Kennedy," 29 June 2018 And with Chancellor Angela Merkel now weakened within her domestic political party, the success of the proposals remains uncertain. Tom Fairless, WSJ, "Macron, Merkel Show Unity on Defense and Security," 18 Nov. 2018 Oil had fallen for 12 straight days as of Tuesday, driven by worries over rising oil production around the world and weakening demand from developing countries. Alex Veiga, The Seattle Times, "Energy companies lead US stocks higher as oil prices rebound," 14 Nov. 2018 Currently, there are two pending cases over previous San Francisco ballot measures that could either strengthen or weaken Prop C’s legal footing. Shirin Ghaffary, Recode, "San Francisco’s Prop C homelessness tax was a big win for Marc Benioff, but legal challenges may be coming," 8 Nov. 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

8 Dec 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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More from Merriam-Webster on weaken

Rhyming Dictionary: Words that rhyme with weaken

Thesaurus: All synonyms and antonyms for weaken

Spanish Central: Translation of weaken

Nglish: Translation of weaken for Spanish Speakers

Britannica English: Translation of weaken for Arabic Speakers

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).


to move with a clumsy heavy tread

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