flaw

flaw — noun

1. a small problem in something such as an object, a plan, or someone's character t

1.nounB1
Definition

a small problem in something such as an object, a plan, or someone's character that stops it from being perfect

Example

A small flaw in the diamond made it less valuable than the others.

Samir spotted a flaw in the argument that everyone else had missed.

collocation: spot a flaw in [something]

Common collocations
  • serious flaw
  • major flaw
  • character flaw
  • design flaw
  • flaw in the argument
  • flaw in the plan
  • spot a flaw
  • find a flaw
  • have a flaw
  • reveal a flaw
Synonyms
  • defect

    suggests a more serious or structural problem; a defect often means something is unfit for its purpose

  • imperfection

    gentler and often about surface-level or cosmetic issues rather than functional faults

  • weakness

    broader — can refer to ability or vulnerability under pressure, not only fixed flaws

Antonyms

Grammar Patterns

flaw + in + noun phrase

Usage Note

Commonly followed by 'in' to specify where the imperfection lies (a flaw in the design, a flaw in her logic). Can be used with physical objects, abstract plans, or personal character — the core idea is always something that prevents full quality.

Common Mistakes

I made a flaw in the calculation.
I made a mistake in the calculation.
a flaw is a built-in weakness or imperfection, not a one-time error in action.
The flaw of the plan is the cost.
The flaw in the plan is the cost.
flaw is followed by 'in', not 'of', when describing what has the imperfection.

flaw — verb

Word family

  • flawed
    adjectiveB2
  • flawless
    adjectiveB2
  • flawlessly
    adverbC1
  • flawlessness
    nounC1

Synonym discussion

Sense: noun/1

All four words describe something wrong, but they differ in scope and register. 'Flaw' is the most general — it covers physical cracks, character weaknesses, and logical errors equally well. 'Defect' leans toward manufacturing or mechanical problems and often implies something is unfit for use (a defective product cannot function properly). 'Imperfection' is the gentlest term, used for surface-level or cosmetic issues rather than serious faults — a small scratch is an imperfection, not a defect. 'Weakness' is broader and applies to ability, structure, or character; it suggests vulnerability under pressure rather than a fixed imperfection — you can overcome a weakness, but a flaw is permanent. 'Fault' overlaps with 'flaw' but also carries a sense of blame or responsibility ('It's my fault'). For a physical object, use 'flaw' for a small crack and 'defect' when it prevents proper function. For a person, 'character flaw' is a fixed trait, while 'weakness' may be temporary or situational.

Common collocations

Nouns

Phrases

  • without flaw
  • free of flaws

Prepositions

Etymology

Old NorseMiddle EnglishEnglish

Flaw came into English from Old Norse 'flaga', meaning a stone slab or a layer. In the 1300s it referred to a chip or crack in a piece of stone. Over the centuries the meaning broadened from a physical crack to any kind of imperfection — in a person's character, a plan, or an argument.