English Reference

Word

impaired

Phoneticsim·paired, stress on the second syllable

US/ˌɪmˈpɛɹd/

UK/ɪmpˈeəd/

Definitions

01weakened or damaged

B2 · Upper Intermediate Formal

adj. damaged or weakened so that it does not work perfectly.

adj. rendered less effective, weakened, or damaged in function or quality.

“His vision was impaired after the accident, so he had to wear glasses.”

“The patient's cognitive functions were significantly impaired by the stroke, necessitating a long-term rehabilitation plan focused on speech and memory.”

Usage

Often used in medical or technical contexts to describe senses like hearing or vision.

Antonyms

02drunk or high

C1 · Advanced Law Formal · Technical

adj. not able to think or act clearly because of alcohol or drugs.

adj. functioning at a diminished capacity due to the consumption of alcohol or controlled substances.

“The police stopped the driver because he appeared to be impaired.”

“Operating heavy machinery while impaired by prescription medication is strictly prohibited under the current safety guidelines.”

Teaching tip

This is a formal and legal way to say someone is drunk or high; it is the standard term used in police reports and courtrooms.

Antonyms

03a legal charge

C2 · Proficiency Countable noun Law American English · Technical

n. a crime where someone drives a car while they are drunk or high.

n. a criminal offence involving the operation of a motor vehicle while under the influence of intoxicants.

“He lost his license after being charged with an impaired.”

“The defendant faced a mandatory minimum sentence after his second impaired in three years.”

Usage

Used as a countable noun primarily in North American legal contexts.

Synonyms

DUIdrunk driving

Real-World Examples

“Performance was impaired when checked 15 minutes, four hours, eight hours and 24 hours later.”
BBC News 15 Aug 2026
“A four-hour delay was corrected 50% faster in mice, and six-hour shifts in macaques were reduced by about one day, without impaired sleep or major toxicity.”
Phys.org 14 Aug 2026

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
Frequency
Frequent
Level
B2 · Upper Intermediate
Updated

QR code

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English Reference