Synonyms of weak

weak

adjective

ˈwēk 

1

as in weakened

lacking bodily strength

the little boy was simply too weak to lift the box

Synonyms & Similar Words

• weakened
• feeble
• frail
• disabled
• faint
• enfeebled
• debilitated
• wimpy
• soft
• paralyzed
• infirm
• slight
• vulnerable
• tired
• low
• softened
• wasted
• exhausted
• asthenic
• unsubstantial
• injured
• languid
• fragile
• incapacitated
• delicate
• prostrate
• down-and-out
• wimpish
• effete
• weary
• enervated
• sapped
• tender
• invalid
• prostrated
• unsteady
• powerless
• drained
• impotent
• damaged
• decrepit
• dizzy
• flimsy
• hurt
• susceptible
• impaired
• rocky
• breakable
• groggy
• woozy
• broken-down
• flagging
• unsound
• resistless
• yielding
• harmed
• worn-out
• unresistant

Antonyms & Near Antonyms

• strong
• powerful
• mighty
• stout
• muscular
• rugged
• tough
• athletic
• stalwart
• robust
• hard
• virile
• sturdy
• beefy
• fit
• brawny
• hardy
• sinewy
• husky
• strengthened
• lusty
• hardened
• vigorous
• able-bodied
• energetic
• fortified
• healthy
• sound
• capable
• competent
• energized
• strapping
• toughened
• hale
• recovering
• red-blooded
• inured
• invigorated
• vitalized
• convalescing
• recuperating

2

as in soft

lacking strength of will or character

I was too weak to resist the free doughnuts in the office break room

Synonyms & Similar Words

• weakened
• soft
• frail
• meek
• corrupt
• timid
• wimpy
• spineless
• wet
• wimpish
• nerveless
• characterless
• weakling
• invertebrate
• weak-kneed
• effete
• milk-and-water
• wishy-washy
• ineffective
• ineffectual
• flabby
• limp-wristed
• powerless
• flaccid
• impotent
• namby-pamby
• craven
• forceless
• villainous
• emasculated
• submissive
• unnerved
• unscrupulous
• unprincipled
• pliable
• pusillanimous
• cowardly
• lamblike
• infirm
• irresolute
• dastardly
• impuissant
• sissy
• fainthearted
• vacillating
• nebbishy
• lily-livered
• poltroon

Antonyms & Near Antonyms

• strong
• tough
• hard
• good
• firm
• moral
• right
• virtuous
• righteous
• ethical
• upright
• principled
• backboned
• resolute
• unrelenting
• determined
• courageous
• stalwart
• mettlesome
• stouthearted

3

as in thin

not containing very much of some important element

the coffee came out too weak because I didn't use enough ground beans

Synonyms & Similar Words

• thin
• dilute
• diluted
• thinned
• weakened
• washy
• watery
• adulterated
• watered-down

Antonyms & Near Antonyms

• strong
• rich
• fortified
• enriched
• concentrated
• full-bodied
• condensed
• evaporated

4

as in unreasonable

not using or following good reasoning

your argument is weak

Synonyms & Similar Words

• unreasonable
• irrational
• unreasoning
• illegitimate
• misleading
• foolish
• unreasoned
• illogical
• invalid
• absurd
• silly
• fallacious
• inconsistent
• unsound
• inconsequential
• weird
• inconsequent
• nonrational
• meaningless
• unusual
• odd
• strange
• specious
• misguided
• insane
• random
• sophistic
• disorganized
• unconvincing
• disordered
• unconsidered
• nonsensical
• mad
• asinine
• surreal
• inexplicable
• ill-advised
• eristic
• half-baked
• unaccountable
• nutty
• wacky
• peculiar
• preposterous
• senseless
• unexplainable
• rambling
• reasonless
• Kafkaesque

Antonyms & Near Antonyms

• reasonable
• valid
• logical
• sound
• rational
• wise
• sensible
• sane
• solid
• sober
• justified
• enlightened
• just
• reasoned
• clear
• informed
• well-founded
• convincing
• certain
• compelling
• well-grounded
• plausible
• persuasive
• true
• organized
• satisfying
• credible
• sure
• commonsense
• ordered
• demonstrated
• cogent
• confirmed
• established
• validated
• substantiated
• corroborated

5

as in helpless

unable to act or achieve one's purpose

the vice president is a relatively weak official

Synonyms & Similar Words

• helpless
• paralyzed
• incompetent
• powerless
• impotent
• passive
• high and dry
• incapable
• feeble
• useless
• ineffective
• unfit
• handcuffed
• ineffectual
• hamstrung
• impuissant
• hog-tied
• infirm
• inept
• spineless
• frail
• supine
• unaggressive

Antonyms & Near Antonyms

• strong
• powerful
• mighty
• effective
• able
• capable
• potent
• efficient
• competent
• dominant
• important
• dynamic
• authoritarian
• tough
• robust
• vigorous
• autocratic
• major
• significant
• sturdy
• energetic
• forceful
• puissant
• tyrannical
• despotic
• dictatorial
• senior
• top
• high-level
• magisterial

Synonym Chooser

How does the adjective weak contrast with its synonyms?

Some common synonyms of weak are decrepit, feeble, fragile, frail, and infirm. While all these words mean "not strong enough to endure strain, pressure, or strenuous effort," weak applies to deficiency or inferiority in strength or power of any sort.

felt weak after the surgery

When is it sensible to use decrepit instead of weak?

The synonyms decrepit and weak are sometimes interchangeable, but decrepit implies being worn-out or broken-down from long use or old age.

the dowager's decrepit retainers

In what contexts can feeble take the place of weak?

Although the words feeble and weak have much in common, feeble suggests extreme weakness inviting pity or contempt.

a feeble attempt to walk

When might fragile be a better fit than weak?

While in some cases nearly identical to weak, fragile suggests frailty and brittleness unable to resist rough usage.

a reclusive poet too fragile for the rigors of this world

When is frail a more appropriate choice than weak?

The meanings of frail and weak largely overlap; however, frail implies delicacy and slightness of constitution or structure.

a frail teenager unable to enjoy sports

Where would infirm be a reasonable alternative to weak?

The words infirm and weak are synonyms, but do differ in nuance. Specifically, infirm suggests instability, unsoundness, and insecurity due to old age or crippling illness.

infirm residents requiring constant care

Example Sentences

Recent Examples of weak

Using computer models, the researchers found that pockets of salt-rich ice near Europa's surface can become both denser and mechanically weaker than surrounding, purer ice. —Sharmila Kuthunur, Space.com, 23 Jan. 2026

Because unresolved tension feels like weak leadership. —Vibhas Ratanjee, Forbes.com, 23 Jan. 2026

But the jet stream periodically gets weak and wavy. —Rebecca Hersher, NPR, 23 Jan. 2026

The struggling chipmaker gave a weak sales outlook for the current quarter, even though its financial results in the last three months of 2025 came in ahead of targets. —Alexei Oreskovic, Fortune, 23 Jan. 2026