Synonyms for Weak

Updated 2026-10-03 · Synonyms List editorial team

Quick answer: Synonyms for weak describe a lack of physical strength, mental resolve, or structural integrity. Finding the precise term helps convey whether a subject is frail, hesitant, or simply lacking potency. This guide categorizes these words by tone and context for accurate usage.

Closest Synonyms for Weak

frail: Suggests delicate physical constitution requiring care. The elderly woman looked frail as she walked to the window.
feeble: Implies a total lack of vigor or energy. His feeble attempt to lift the box failed immediately.
feebleminded: Indicates a lack of intellectual capacity or judgment. Critics dismissed the plan as feebleminded and poorly conceived.
flimsy: Describes something poorly constructed or lacking substance. The flimsy cardboard box collapsed under the weight of the books.
fragile: Highlights susceptibility to breaking or damage. The fragile glass vase needed to be wrapped in bubble wrap.
infirm: Refers specifically to weakness due to age or illness. The infirm patient required a wheelchair for all hospital visits.
languid: Suggests a slow, relaxed, or listless energy. She spent a languid afternoon reading by the poolside.
limp: Indicates a lack of stiffness or firmness. The wet paper towel felt limp and useless in her hand.
sluggish: Describes slow movement or reaction speed. The computer ran sluggish after installing too many background apps.
wan: Refers to a pale or weak appearance, often of color or light. The wan smile did not reach his tired eyes.
watered-down: Means diluted in strength or intensity. The committee rejected the watered-down proposal for lacking ambition.
withered: Implies shriveling or drying up from age or neglect. The withered leaves crumbled at the slightest touch.

Formal Synonyms for Weak

attenuated: Thinned or weakened in force or effect. The signal became attenuated as it traveled through the dense walls.
diminished: Reduced in size, amount, or importance. His influence was diminished after the scandal made headlines.
enfeebled: Made weak or feeble, often by disease. The enfeebled state of the economy worried investors globally.
impaired: Weakened or damaged in function. His vision was impaired by the intense brightness of the sun.
ineffectual: Not producing any or the desired result. The manager was viewed as ineffectual during the crisis meetings.
infirmed: Affected by physical weakness or illness. The infirmed veteran struggled to climb the steep stairs.
lacking: Not having enough of a particular quality. The report was lacking in detailed statistical evidence.
waning: Decreasing in vigor or intensity. Her interest in the project showed signs of waning.
diminutive: Extremely small in size or amount. The diminutive structure could not withstand the heavy snowfall.

Informal Synonyms for Weak

blah: Unexciting, dull, or lacking energy. The movie was so blah that half the audience fell asleep.
crummy: Of poor quality or inferior. The crummy coffee tasted like burnt rubber and stale water.
frazzled: Feeling extremely tired and nervous. The frazzled teacher struggled to keep order in the chaotic class.
jittery: Nervous or agitated with shaky movements. He felt jittery from drinking too much coffee before the exam.
lame: Unconvincing or inadequate; poor quality. The comedian delivered a lame joke that got no laughs.
meh: Mediocre or indifferent; lacking passion. Her reaction to the news was just a simple meh.
off: Not quite right or lacking its usual quality. The milk tasted a bit off, so we poured it out.
scrawny: Unusually thin and weak-looking. The scrawny puppy needed more food to gain healthy weight.
washed-out: Faded or drained of color or energy. The washed-out fabric looked old and unwearable.

Stronger and Weaker Words

incapacitated: Stronger than weak. Use when someone is completely unable to function due to injury or illness.
anemic: Stronger than weak. Use to describe something severely lacking in substance or vitality.
mild: Weaker than weak. Use for something gentle or moderate, not overpowering.
soft: Weaker than weak. Use for gentle pressure or lack of hardness, not necessarily frailty.
pale: Weaker than weak. Use for lightness of color or slight lack of intensity.
subtle: weaker; choose this when referring to a quality that is delicate, understated, or difficult to notice rather than lacking power.
slight: weaker; use this to indicate a small degree of intensity or magnitude, such as a slight breeze or a slight inconvenience.

Antonyms for Weak

strong
powerful
robust
sturdy
vigorous
resilient
potent
forceful
hardy
mighty

How to Pick the Right Synonym

Choose your synonym based on the specific type of weakness you want to describe. Use physical terms like frail or feeble for bodies, structural words like flimsy for objects, and abstract terms like ineffectual for arguments or plans. Consider the tone: formal writing benefits from attenuated or diminished, while casual speech might prefer lame or crummy. Always ensure the word matches the severity of the situation.

Best Synonym by Situation

Describing a shy person: Use timid. The timid child hid behind her mother's legs.
Describing a fragile object: Use delicate. The delicate vase shattered upon hitting the floor.
Describing a lacking argument: Use tenuous. The suspect's alibi was tenuous and easily disproven.
Describing a sick patient: Use frail. The frail grandmother needed assistance walking.
Describing a pale complexion: Use wan. His face looked wan after a night without sleep.
Describing a poor performance: Use lackluster. The team delivered a lackluster effort in the final quarter.
Describing a thin structure: Use flimsy. The flimsy cardboard box could not hold heavy books.
Describing a gentle breeze: Use faint. A faint scent of lavender drifted through the open window.
Describing a low-energy mood: Use lethargic. The hot weather made everyone feel lethargic and slow.
Describing a minor injury: Use slight. She suffered only a slight bruise from the fall.

Example Sentences

The old rope was too brittle to support the weight of the swing.
His voice was feeble and barely audible over the noise of the crowd.
The argument was flimsy and collapsed under closer scrutiny.
She felt faint and had to sit down immediately.
The structure was precarious and likely to collapse in the wind.
The tea had a mild flavor that pleased the whole family.
His grip was limp as he handed over the keys.
The signal was faint, making it hard to connect to the server.
The fabric was sheer and offered little protection from the sun.
The excuse sounded far-fetched and unconvincing to the judge.

Related Phrases and Idioms

As fragile as glass: Extremely breakable or sensitive to pressure.
On the ropes: In a difficult situation with little hope of recovery.
A weak link: The least strong part of a group or chain.
Faint heart: Lacking courage or determination.
On shaky ground: In an unstable or uncertain position.
Barely hanging on: Surviving with great difficulty and minimal resources.

Frequently Asked Questions

What is the difference between weak and frail?

Weak generally refers to a lack of physical strength or power, while frail specifically implies a delicate constitution that is easily broken or damaged, often due to age or illness.

Is weak an adjective or a noun?

Weak is primarily an adjective, describing a quality of lacking strength. It can occasionally function as a noun in specific contexts, such as referring to weak people collectively, but this usage is rare.

Can weak describe an argument?

Yes, weak is frequently used to describe arguments, evidence, or logic that lacks persuasiveness, validity, or strength. Synonyms in this context include flimsy, specious, or unconvincing.

What is the opposite of weak?

The direct opposite of weak is strong. Other antonyms include powerful, robust, sturdy, and vigorous, depending on whether you are discussing physical strength, mental fortitude, or structural integrity.