deficient
deficient — adjective
1. containing less of something than what is necessary to stay healthy, function we
containing less of something than what is necessary to stay healthy, function well, or achieve a goal.
Niran's diet was deficient in iron, so the doctor gave him supplements.
deficient in [nutrient]
The soil in this region is deficient in nitrogen, which affects crop growth.
Eating only white rice made Yuki's diet deficient in iron, causing anaemia.
Femi's lab mice on a corn-only diet were deficient in lysine, an essential amino acid.
Paloma's research paper was rejected because it was deficient in supporting evidence.
- lacking
less formal, used in everyday speech
- insufficient
focuses on quantity or amount being too low
- inadequate
emphasises that the amount fails to meet a specific need
- sufficient
having enough of what is needed
- adequate
enough to meet a particular requirement
- abundant
having more than enough
文法句型
deficient in + [noun]
用法筆記
Frequently used with the preposition 'in' to specify what is lacking. Common in medical, nutritional, and academic writing. Not used in informal conversation about everyday shortages — for those, use 'short of' or 'low on'.
常見錯誤
2. below an acceptable standard of quality, completeness, or performance.
below an acceptable standard of quality, completeness, or performance.
The brakes on Mizuki's car were found to be deficient during the safety inspection.
deficient in safety-related contexts
Yael argued that the company's emergency plan was deficient in several key areas.
School inspectors rated the teaching as deficient and ordered immediate improvements.
Kasia returned the product because its packaging was deficient and the items arrived damaged.
Lien found the training programme deficient in practical skills development for new staff.
- defective
more specific — having a clear flaw or broken part
- substandard
below an expected or required level
- flawed
having imperfections or weaknesses
- unsatisfactory
not meeting expectations, broader in meaning
- satisfactory
meeting the expected standard
- acceptable
good enough to be approved
- adequate
just meeting the required level
文法句型
deficient in + [noun/gerund]
be + deficient
用法筆記
Common in formal evaluations of quality, compliance, or performance. For everyday objects with physical flaws, 'defective' or 'faulty' is more natural. This sense also often appears in technical reports and official assessments.
常見錯誤
deficient — noun
1. someone or something that fails to meet the expected standard or lacks what is r
someone or something that fails to meet the expected standard or lacks what is required.
Felix marked any circuit board that failed the voltage test as a deficient requiring rework.
deficient as countable noun in manufacturing
Rachel's safety inspection rated the emergency exit as a deficient in the official report.
The old medical files described the children as mental deficients, a term now considered offensive.
Tuan logged each contaminated sample as a deficient in the quality-control database.
The building inspector marked the wiring system as a deficient in his final report.
- defective
more common for objects with flaws
- reject
specific to manufacturing quality control
- imperfect item
clearer and less technical
- acceptable item
meets the required standard
- pass
in quality-control testing
文法句型
a/the deficient
deficients (plural)
用法筆記
The countable noun form is relatively rare in modern English. In historical medical usage, 'mental deficient' was a clinical label that is now considered outdated and derogatory. In contemporary contexts, this noun appears mostly in quality-control, auditing, or technical classifications.