weak·​en ˈwē-kən How to pronounce weaken (audio)
weakened; weakening
ˈwē-kə- How to pronounce weaken (audio)
; weakens

transitive verb

: to make weak : lessen the strength of
: to reduce in intensity or effectiveness

intransitive verb

: to become weak
ˈwē-kə- How to pronounce weaken (audio)
Choose the Right Synonym for weaken

weaken, enfeeble, debilitate, undermine, sap, 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

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. See More
Recent Examples on the Web The renminbi, meanwhile, has weakened on the country’s sluggish economic recovery from the pandemic. Kristin Broughton, WSJ, 30 Nov. 2023 Money sluicing out of China has weakened the currency, the renminbi, against the dollar and other currencies. Joy Dong, New York Times, 28 Nov. 2023 Combined with lower turnout, that weakens their influence. Gabriella Abdul-Hakim, ABC News, 28 Nov. 2023 The latest quarterly results from a string of retailers from Walmart to Best Buy have reported a weakening consumer. Democrat-Gazette Staff From Wire Reports, arkansasonline.com, 24 Nov. 2023 Gas prices have plunged due to a combination of weakening oil prices and flattening demand for gasoline, according to AAA. Elizabeth Napolitano, CBS News, 23 Nov. 2023 But confidence in the former hotspot has weakened since 2019 as the number of UHCERs detected from there appears to be dropping. Jennifer Ouellette, Ars Technica, 23 Nov. 2023 But this Walker circulation pattern weakens during an El Niño. Tom Yulsman, Discover Magazine, 22 Nov. 2023 These programs arrive just as the economics of green energy are weakening. Shawn Tully, Fortune, 11 Nov. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'weaken.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1530, in the meaning defined at transitive sense 1

Time Traveler
The first known use of weaken was in 1530

Dictionary Entries Near weaken

Cite this Entry

“Weaken.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/weaken. Accessed 5 Dec. 2023.

Kids Definition


weak·​en ˈwē-kən How to pronounce weaken (audio)
weakened; weakening ˈwēk-(ə-)niŋ How to pronounce weaken (audio)
: to make or become weak or weaker

More from Merriam-Webster on weaken

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