Deficient

adj, noun

adj, noun ·3 syllables ·Common ·High school level

Definitions

Noun
  1. 1
    A person who is deficient.

    "This was justified by the rationale that mental deficients, by definition, are not able to succeed in society."

Adjective
  1. 1
    Lacking something essential; often construed with in.

    "They were deficient in social skills."

  2. 2
    Insufficient or inadequate in amount.

    "Apothecia lecanoroid; multilocular; each cell containing a single theke; paraphyses deficient."

  3. 3
    Of a number n, Having the sum of divisors σ(n)<2n, or, equivalently, the sum of proper divisors (or aliquot sum) s(n)<n.
Adjective
  1. 1
    inadequate in amount or degree wordnet
  2. 2
    falling short of some prescribed norm wordnet
  3. 3
    of a quantity not able to fulfill a need or requirement wordnet

Synonyms

All synonyms
inadequateinsufficientleanthreadbareabsentadulterated

Example

More examples

"The young engineer was deficient in experience."

Etymology

From Latin deficiens, present participle of deficere (“to lack, fail, be wanting”); see defect.

Related phrases

deficient numberdeficient-demand unemploymentdemand-deficient unemploymentmental deficientrank-deficientself-deficient

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Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.