weaken

American  

[wee-kuhn] / ˈwi kən /

verb (used with object)

1. to make weak or weaker.

   Synonyms:

   invalidate, minimize, impair, reduce, lower, diminish, lessen, deplete, exhaust, sap, undermine, enervate, debilitate, enfeeble

   Antonyms:

   strengthen

2. Phonetics. to change (a speech sound) to an articulation requiring less effort, as from geminate to nongeminate or from stop to fricative.

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verb (used without object)

1. to become weak or weaker.

   Synonyms:

   sap, undermine, enervate, debilitate, enfeeble, invalidate, minimize, impair, reduce, lower, diminish, lessen, deplete, exhaust

   Antonyms:

   strengthen

weaken British  

/ ˈwiːkən /

verb

1. to become or cause to become weak or weaker

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Other Word Forms

• reweaken verb
• unweakened adjective
• unweakening adjective
• weakener noun

Etymology

Origin of weaken

First recorded in 1520–30; weak + -en ¹

Example Sentences

“On the one hand, raising the policy rate to bring down inflation could weaken the economy further. On the other hand, lowering rates to support the economy could risk pushing inflation even higher.”

From The Wall Street Journal • Apr. 1, 2026

Higher interest rates can damp metal demand and weaken the appeal of nonyielding assets, like gold.

From The Wall Street Journal • Mar. 24, 2026

Oil-price shocks can lead to stagflation, increasing prices for gasoline and food at the same time they weaken demand and the labor market.

From MarketWatch • Mar. 23, 2026

However, these same reactions can also weaken enamel, making teeth more vulnerable to future discoloration and other issues.

From Science Daily • Mar. 23, 2026

I think of the trail of destruction in my wake—my knees weaken and I slide down to a sitting position.

From "Mockingjay" by Suzanne Collins

Related Words

• abate
• decline
• decrease
• depress
• dilute
• diminish
• dwindle
• halt
• impair
• lessen
• lower
• reduce
• sap
• soften
• undermine
• wane