Synonyms of weaken

weaken

verb

ˈwē-kən 

1

as in to soften

to diminish the physical strength of

weeks of hardship in the desert had greatly weakened them

Synonyms & Similar Words

• soften
• injure
• debilitate
• hurt
• enfeeble
• waste
• exhaust
• paralyze
• tire
• sap
• enervate
• damage
• impair
• cripple
• deplete
• depress
• devitalize
• incapacitate
• prostrate
• harm
• disable
• etiolate
• impoverish
• hamstring
• invalid
• grind (down)
• lay up
• wash out
• unman
• wear out
• wear down
• break down

Antonyms & Near Antonyms

• strengthen
• fortify
• recruit
• energize
• harden
• beef (up)
• invigorate
• season
• rejuvenate
• vitalize
• toughen

2

as in to fade

to lose bodily strength or vigor

the bodybuilder weakened once she eased off on her workouts

Synonyms & Similar Words

• fade
• sag
• fail
• go
• deteriorate
• sink
• wilt
• decay
• wither
• droop
• languish
• waste (away)
• lag
• emaciate
• flag
• rot
• yield
• wear out
• break down
• degenerate
• run down

Antonyms & Near Antonyms

• recover
• recuperate
• rebound
• rally
• gain
• convalesce

3

as in to dilute

to alter (something) for the worse with the addition of foreign or lower-grade substances

weakened the juice with too much water

Synonyms & Similar Words

• dilute
• infect
• cut
• pollute
• poison
• thin
• manipulate
• load
• extend
• dirty
• spoil
• adulterate
• degrade
• water down
• contaminate
• taint
• soil
• lace
• corrupt
• debase
• cheapen
• sophisticate
• defile
• misrepresent
• temper
• attenuate
• sully
• falsify
• qualify
• counterfeit
• moderate
• foul
• befoul
• tamper (with)
• spike
• envenom
• fake
• fudge
• doctor

Antonyms & Near Antonyms

• strengthen
• enrich
• fortify
• reinforce
• augment
• supplement
• fertilize
• improve
• better
• purify
• enhance
• refine
• clarify
• richen
• clean
• decontaminate
• cleanse
• purge
• flush
• leach
• filter
• distill
• lard
• concentrate
• compact
• condense
• pasteurize

Synonym Chooser

How is the word weaken distinct from other similar verbs?

Some common synonyms of weaken are cripple, debilitate, disable, enfeeble, sap, and undermine. While all these words 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

When would cripple be a good substitute for weaken?

While in some cases nearly identical to weaken, cripple implies causing a serious loss of functioning power through damaging or removing an essential part or element.

crippled by arthritis

Where would debilitate be a reasonable alternative to weaken?

The words debilitate and weaken can be used in similar contexts, but debilitate suggests a less marked or more temporary impairment of strength or vitality.

the debilitating effects of surgery

When could disable be used to replace weaken?

While the synonyms disable and weaken are close in meaning, disable suggests bringing about impairment or limitation in a physical or mental ability.

disabled by an injury sustained at work

When might enfeeble be a better fit than weaken?

The synonyms enfeeble and weaken are sometimes interchangeable, but enfeeble implies a condition of marked weakness and helplessness.

enfeebled by starvation

How are the words undermine and sap related as synonyms of weaken?

Both 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

Example Sentences

Recent Examples of weaken

Airlines spent 13 years trying to weaken Europe's consumer protections. — Christopher Elliott, Forbes.com, 22 Aug. 2026

But in the summer of 2006 Arsenal weakened themselves — Dennis Bergkamp, Robert Pires, Sol Campbell, Ashley Cole and Jose Antonio Reyes all departed. — Amy Lawrence, New York Times, 22 Aug. 2026

Ash trees are prone to emerald ash borers that weaken the wood and risk damage from brittle limbs that eventually fall. — Karen Brewer Grossman, Southern Living, 22 Aug. 2026

Starting in 2021, China’s real estate slowdown weakened domestic demand for steel, cement, and other construction materials. — Alvin Camba, Foreign Affairs, 21 Aug. 2026