insufficient

insufficient — adjective

1. relating to a situation where the amount of something available falls short of w

1.adjectiveC1
Definition

relating to a situation where the amount of something available falls short of what the situation demands — for instance, when the money you have saved is not enough to pay a large bill.

Example

The committee concluded that the evidence was insufficient to support the claim.

pattern: insufficient + to-infinitive

Ravi's application was rejected because of his insufficient work experience.

Common collocations
  • insufficient evidence
  • insufficient funds
  • insufficient time
  • insufficient data
  • insufficient information
  • insufficient resources
  • insufficient to + verb
Synonyms
  • inadequate

    more common regarding quality or capability rather than pure quantity ('inadequate training' vs 'insufficient funds')

  • deficient

    suggests a specific element is missing or below standard, often in technical or nutritional contexts

  • scarce

    describes a resource that is in short supply relative to demand, rather than simply not enough for a purpose

Antonyms
  • sufficient

    direct opposite; B1-level word meaning as much as needed

  • adequate

    implies enough for the purpose, often with a sense of 'barely enough'

  • enough

    the most common and neutral opposite; used across all registers

Grammar Patterns

insufficient + to-infinitive

insufficient + noun phrase

Usage Note

Frequently used in formal, professional, and academic contexts rather than in everyday conversation. The subject is usually an abstract noun such as evidence, funds, time, data, or resources. In casual speech, 'not enough' is more natural than 'insufficient'.

Common Mistakes

The soup was insufficient.
There was not enough soup.
'Insufficient' sounds unnatural with concrete everyday objects like food in simple statements; use 'not enough' instead.
I have insufficient money to buy the ticket.
I do not have enough money to buy the ticket.
In everyday spoken English, 'not enough' is preferred over 'insufficient'.

Word family

  • insufficiently
    adverbC1
  • insufficiency
    nounC1
  • sufficient
    adjectiveB1
  • sufficiently
    adverbB2
  • sufficiency
    nounC2

Synonym discussion

Sense: adjective/1

Insufficient, inadequate, deficient, and lacking all describe something that does not meet a requirement, but they differ in emphasis and usage. Insufficient is the most neutral and formal term, used primarily for quantities that fall short of what is needed ('insufficient funding for the project'). Inadequate often shifts the focus from quantity to quality or capability, suggesting that something is not good enough for its purpose ('inadequate safety measures'). Deficient tends to be more technical, implying that a specific necessary element is missing or below a required standard ('a diet deficient in vitamin C'). Lacking is the most informal of the four and typically requires a complement introduced by 'in' ('the proposal was lacking in detail'). For everyday speech, 'not enough' is simpler and more natural than any of these. For example: 'The evidence was insufficient for a conviction' (quantity) contrasts with 'The defense's argument was inadequate' (quality) or 'The investigation was deficient in thoroughness' (a specific missing element).

insufficientinadequatedeficientlacking

Common collocations

Adverbs

  • woefully insufficient
  • grossly insufficient
  • clearly insufficient
  • simply insufficient

Prepositions

  • insufficient for

Etymology

LatinFrenchEnglish

From Latin 'in-' (a prefix meaning 'not') combined with 'sufficere' (to provide what is needed). The word passed into English through Old French 'insuffisant' and has been recorded in English usage since the 14th century.