# mad

/ˈmæd/ (US) · /mˈæd/ (UK)

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

## Senses

### 2. mentally ill

adjective · CEFR B1 · British English

having a mind that does not work in a healthy way; mentally ill.

For teachers: suffering from a mental illness or being extremely foolish. This is the primary sense in British English.

- The old stories tell of a king who went mad and talked to the trees.
- In nineteenth-century literature, characters were often described as going mad when they could no longer cope with social pressures.

Usage: Often used in the phrase 'go mad'.

Teaching tip: In modern contexts, using this to describe mental health can be seen as insensitive; 'mentally ill' is the neutral alternative.

### 3. very enthusiastic

adjective · CEFR B1 · Informal

liking something very much or being very excited about it.

For teachers: extremely enthusiastic about or fond of something.

- My brother is mad about football and never misses a game.
- She was mad about jazz in her youth, spending every spare penny on vinyl records and concert tickets.

Usage: Usually followed by the preposition 'about'.

### 4. foolish or irrational

adjective · CEFR B2

very silly, stupid, or not making any sense.

For teachers: extremely foolish, unwise, or irrational.

- It was a mad idea to go hiking in the middle of a thunderstorm.
- The plan to expand the factory without securing extra funding was seen by many as a mad gamble.

### 5. very or extremely

adverb · CEFR C1 · Slang · American English

used to mean 'very' or 'extremely' to make an adjective stronger.

For teachers: used as an intensifier to mean 'extremely' or 'very'.

- That new video game is mad expensive, so I have to save up for it.
- The concert was mad loud, but the atmosphere was incredible despite the noise levels.

## Examples

- Please don't be mad at me for being late.
- He was so mad about the broken window that he refused to speak to anyone for the rest of the afternoon.
- The protagonist's descent into a mad obsession with the past eventually alienates his few remaining friends, leaving him isolated in his sprawling estate.

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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.