verb weak·en \ ˈwē-kən \
|Updated on: 4 Aug 2018

Definition of weaken

weakened; weakening play \ˈwēk-niŋ, ˈwē-kə-\
1 : to make weak : lessen the strength of
2 : to reduce in intensity or effectiveness
: to become weak


play \ˈwēk-nər, ˈwē-kə-\ noun

Examples of weaken in a Sentence

  1. The disease weakens the immune system.

  2. Some are concerned that the increase in taxes will weaken the economy.

  3. The beams had been weakened by water damage.

  4. efforts to weaken environmental laws

  5. The recent setbacks have not weakened our resolve.

  6. These kinds of contradictions weaken your argument.

  7. The disease causes the immune system to weaken.

  8. The dollar has continued to weaken against the euro.

  9. Lower interest rates have weakened the dollar.

Recent Examples of weaken from the Web

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.

First Known Use of weaken


in the meaning defined at transitive sense 1

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Synonym Discussion of 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

WEAKEN Defined for English Language Learners


Definition of weaken for English Language Learners

  • : 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

WEAKEN Defined for Kids


verb weak·en \ ˈwē-kən \

Definition of weaken for Students

weakened; weakening
: 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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