deficiency

noun

de·​fi·​cien·​cy di-ˈfi-shən-sē 

plural deficiencies

1

: the quality or state of being defective or of lacking some necessary quality or element : the quality or state of being deficient : inadequacy

suffers from a deficiency of critical thinking

2

: an amount that is lacking or inadequate : shortage

staffing deficiencies

: such as

a

: a shortage of substances necessary to health

a vitamin C deficiency

hormone deficiencies

b

genetics : deletion sense 2b(1)

Synonyms

• crunch
• dearth
• deficit
• drought
• drouth
• failure
• famine
• inadequacy
• inadequateness
• insufficiency
• lack
• lacuna
• paucity
• pinch
• poverty
• scantiness
• scarceness
• scarcity
• shortage
• undersupply
• want

Examples of deficiency in a Sentence

The disease may be caused by nutritional deficiencies.

The book's major deficiency is its poor plot.

a deficiency of vitamin C

There are several deficiencies in his plan.

The accident was caused by deficiencies in the engine.

Recent Examples on the Web

These common attacks are caused by security deficiencies, including Active Directory misconfigurations, weak password policies, permissive access rules and weak authentication mechanisms. —Reuven Aronashvili, Forbes.com, 7 May 2025

Due to the amount of sodium in the standard American diet, sodium deficiencies are quite rare. —Angelica Bottaro, Verywell Health, 7 May 2025

The review analyzes the remaining portions of the building for structural deficiencies and makes conceptual recommendations for addressing these issues, according to a memo from City Manager Rickelle Williams to the commission sent on Monday. —Susannah Bryan, Sun Sentinel, 6 May 2025

Obviously, the deficiency from 3 was big, but defensively, the versatility. —Kels Dayton, Hartford Courant, 5 May 2025

Word History

Etymology

defici(ent) entry 1 + -ency

First Known Use

1603, in the meaning defined at sense 1

Phrases Containing deficiency

• acquired immune deficiency syndrome
• deficiency disease
• mental deficiency

Rhymes for deficiency

• efficiency
• proficiency
• sufficiency
• immunodeficiency
• inefficiency
• insufficiency

Kids Definition

deficiency

noun

de·​fi·​cien·​cy di-ˈfish-ən-sē 

plural deficiencies

1

: the quality or state of being deficient

2

: the quality or state of being inadequate

especially : a shortage of substances necessary to health

Medical Definition

deficiency

noun

de·​fi·​cien·​cy di-ˈfish-ən-sē 

plural deficiencies

1

: a shortage of substances (as vitamins) necessary to health

2

: deletion

Legal Definition

deficiency

noun

de·​fi·​cien·​cy di-ˈfi-shən-sē 

plural deficiencies

: an amount that is lacking or inadequate: as

a

: the difference between the amount of tax owed and the amount of tax paid

b

: the difference between the amount owed under a security agreement and the amount the creditor is able to recover upon default of the debtor by selling the collateral