Word
insane
Phoneticsin·sane, stress on the second syllable
US/ˌɪnˈseɪn/
UK/ɪnsˈeɪn/
Definitions
01mentally ill
B2 · Upper Intermediate Formal
adj. having a serious mental illness that affects how you think and behave.
adj. exhibiting significant mental derangement or unsoundness of mind. While historically a legal and medical term, it is now often considered insensitive in clinical contexts.
“In the past, people who were considered insane were often kept in large hospitals away from cities.”
“The defendant was found not guilty by reason of being legally insane at the time the crime was committed.”
Synonyms
Antonyms
02ridiculous or extreme
B1 · Intermediate Informal
adj. very foolish, dangerous, or extreme in a way that is hard to believe.
adj. characterized by extreme folly, impracticality, or a lack of common sense.
“It is insane to drive that fast in such heavy rain.”
“The amount of paperwork required for a simple permit is absolutely insane and needs to be streamlined.”
Synonyms
Antonyms
03amazing or impressive
B2 · Upper Intermediate Slang · Informal
adj. extremely good, impressive, or exciting.
adj. used as a superlative to indicate that something is remarkably impressive or excellent.
“The view from the top of the mountain was insane.”
“The lead guitarist performed an insane solo that left the entire audience speechless for a moment.”
Synonyms
04very large or intense
B2 · Upper Intermediate Informal
adj. used to describe a very large amount or a very strong feeling.
adj. denoting an extreme degree of intensity, volume, or scale.
“The band played at an insane volume that made the windows shake.”
“The project required an insane amount of research before we could even begin the design phase.”
Etymology
From Latin īnsānus (“unsound in mind; mad, insane”), from in- + sānus (“sound, sane”), equivalent to in- + sane.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
NOUN
ADJECTIVE
ADVERB
Related words
- 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.B1 PreliminaryIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.4.0–5.0TOEFL 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: 3.0–3.544–71TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.550–784
- Frequency
- Common
- Level
- B1 · Intermediate
- Updated
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