Definitions

deficiency

[dih-fish-uhn-see] / dɪˈfɪʃ ən si /

NOUN

imperfection, inadequacy

Synonyms

STRONGEST

dearth defect failing failure fault flaw frailty glitch insufficiency lack scarcity shortage shortcoming weakness

STRONG

absence bug defalcation default deficit demerit dereliction loss need neglect paucity privation scantiness sin want

WEAK

inability to hack it insufficience

Antonyms

STRONGEST

abundance advantage enough excess perfection plenty strength strong point success sufficiency surplus

STRONG

accomplishment achievement

WEAK

adequacy faultlessness satisfaction superfluity

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The result is a condition that resembles DNA repair deficiency, even in cancer cells that had previously regained their repair capabilities.

From Science Daily • Jun. 10, 2026

Without enough B12, things can go wrong, sometimes seriously, especially if deficiency is not recognized and treated.

From Science Daily • May 27, 2026

Iron deficiency anemia is especially common among pregnant women and adolescent girls in many developing countries.

From Science Daily • May 27, 2026

B12 is clearly essential for the nervous system, and deficiency should not be ignored.

From Science Daily • May 22, 2026

Where there are fewer, the deficiency may be remedied by collecting and distributing the baglike cocoons containing the eggs.

From "Silent Spring" by Rachel Carson

Vocabulary lists containing deficiency

Freak the Mighty

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Flowers for Algernon

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Paltry Parlance: Synonyms for "Few"

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