deficiency

/dɪˈfɪʃnsi/ (bre, ipa) · /dɪˈfɪʃnsi/ (ame, ipa) · /di-ˈfi-shən-sē/ (ame, mw)

deficiency — noun

  • deficiencysingular
  • deficienciesplural

1. a condition in which a person, a system, or a living thing has too little of som

1.名詞B2
釋義

a condition in which a person, a system, or a living thing has too little of something necessary for healthy or proper operation

例句

Haruto's doctor told him he had an iron deficiency, so he started taking supplements.

deficiency + of [specific nutrient]

The soil in Naoko's garden had a mineral deficiency, and her vegetables grew very slowly.

同義詞
  • shortage

    More concrete and usually refers to countable quantities (food, money, staff); 'deficiency' can also describe abstract or internal lacks

  • lack

    A more general and common word; 'lack' is neutral while 'deficiency' often implies that the missing amount is harmful

  • insufficiency

    More formal and technical; common in academic or medical writing

反義詞
  • abundance

    An ample or more-than-adequate supply

  • surplus

    An extra amount beyond what is needed

文法句型

deficiency + of [substance]

deficiency + in [source / location / person]

用法筆記

Often used in medical and nutritional contexts, but also applies to systems, resources, and natural environments. Can be countable ('a vitamin deficiency') or uncountable ('a deficiency of resources').

常見錯誤

❌He has a deficiency of confident.
✅He has a deficiency of confidence.
💡'deficiency of' should be followed by a noun, not an adjective.
❌The team suffered from a deficiency players.
✅The team suffered from a deficiency of players.
💡'deficiency of' needs the preposition 'of' before the noun.

2. a fault, weakness, or problem in someone's character, a plan, a system, or a pro

2.名詞B2
釋義

a fault, weakness, or problem in someone's character, a plan, a system, or a product that makes it less effective or successful than it should be

例句

The project failed because of a serious deficiency in the original plan.

deficiency + in [plan / system]

Gabriel felt that his shyness was a deficiency that held him back at work.

同義詞
  • fault

    More specific; 'fault' often implies blame or responsibility, while 'deficiency' is more neutral and descriptive

  • weakness

    Softer and broader; 'weakness' can be inherent, while 'deficiency' suggests a gap relative to a standard

  • flaw

    Often used for design or physical defects; slightly more specific to objects than people

反義詞
  • strength

    A positive quality or strong point

  • advantage

    A feature that puts something in a favourable position

文法句型

deficiency + in [plan / system / character / product]

用法筆記

Unlike sense 1, this sense focuses on quality or adequacy rather than quantity. It is frequently used with 'in' ('a deficiency in the design') and is common in evaluation contexts (reviews, inspections, performance assessments).

常見錯誤

❌There is a deficiency of the system.
✅There is a deficiency in the system.
💡For faults or weaknesses, use 'deficiency in', not 'deficiency of'.
❌The plan has many lacks.
✅The plan has many deficiencies.
💡'Lack' is not typically used as a countable noun for individual faults; use 'deficiency' or 'weakness' instead.