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.

But B12 deficiency should be considered before folate is prescribed on its own, because folate can improve some blood signs of B12 deficiency while nerve damage continues.

From Science Daily • Jun. 6, 2026

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

From Science Daily • May 27, 2026

"Revisiting the definition of B12 deficiency to incorporate functional biomarkers could lead to earlier intervention and prevention of cognitive decline."

From Science Daily • May 22, 2026

The minimum threshold used to define deficiency may not capture early functional changes in the nervous system.

From Science Daily • May 22, 2026

Cruelly, callously, admissions committees agreed to overlook serious academic deficiency.

From "Hunger of Memory" by Richard Rodriguez

Vocabulary lists containing deficiency

Freak the Mighty

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Flowers for Algernon

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