# crazy

/ˈkɹeɪzi/ (US) · /kɹˈeɪzi/ (UK)

Source: https://englishreference.com/word/crazy
Updated: 2026-06-19

## Senses

### 1. strange or wild

adjective · CEFR A2 · Informal

very strange, unusual, or foolish.

For teachers: not sensible or logical; extremely foolish or strange.

- It was a crazy idea to drive through the storm at night.
- The plan to launch the product without any prior testing seemed crazy to the rest of the board members.

### 2. very enthusiastic

adjective · CEFR A2 · Informal

liking something or someone very much.

For teachers: extremely enthusiastic or fond of a particular person, activity, or object.

- My brother is crazy about football and never misses a game.
- She has been crazy about jazz since she was a teenager, spending most of her weekends at local clubs.

### 3. mentally ill

adjective · CEFR B1 · Informal

having a mind that does not work in a normal way.

For teachers: suffering from a mental illness or being of unsound mind.

- The old stories say a crazy man used to live in that house.
- The defendant's lawyers argued that he was crazy at the time of the incident to avoid a prison sentence.

Usage: Often considered offensive when used to describe people with clinical mental health conditions.

Teaching tip: In modern English, using this word to describe mental illness is often seen as insensitive; advise students to use 'mentally ill' in serious contexts.

### 4. busy or chaotic

adjective · CEFR B1 · Informal

very busy, fast, or full of activity.

For teachers: characterised by chaotic activity or extreme haste.

- Work has been crazy lately with the new project starting.
- The atmosphere in the newsroom became crazy as the election results started pouring in from the coastal districts.

### 5. extremely

adverb · CEFR C1 · Slang · American English

very or extremely.

For teachers: used as an intensifier to mean 'to a great degree'.

- That new video game is crazy expensive.
- The traffic on the bridge was crazy slow this morning due to the construction work.

### 6. an eccentric person

noun · CEFR C1 · Slang · Informal

a person who behaves in a very strange or wild way.

For teachers: a person who is perceived as insane or highly eccentric.

- Don't listen to him; he's just a crazy who shouts at cars.
- The local residents viewed the inventor as a bit of a crazy, despite his obvious technical brilliance.

## Examples

- The traffic in the city is absolutely crazy today.
- The fans went crazy when the singer finally walked onto the stage and started the show.
- While the plan seemed crazy to the conservative board members, the younger investors saw it as a bold and necessary risk for the company's survival.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.