# warn

/ˈwɔɹn/ (US) · /wˈɔːn/ (UK)

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

## Senses

### 1. to alert to danger

verb · CEFR B1

to tell someone that something bad or dangerous might happen.

For teachers: to inform someone in advance of an impending danger, problem, or other unpleasant situation. Transitive, often taking a direct object followed by 'of' or 'about'.

- The radio announcer warned drivers about the thick fog on the motorway.
- Meteorologists warned the coastal residents of the approaching storm, urging them to evacuate before the surge reached the lower streets.

Usage: Commonly used in the patterns 'warn someone of something' or 'warn someone that...'.

### 2. to advise against an action

verb · CEFR B1

to tell someone not to do something because it is a bad idea.

For teachers: to caution or admonish someone against a specific course of action or unacceptable behaviour.

- My doctor warned me not to eat too much salt.
- The legal advisor warned the board against signing the contract without a thorough review of the indemnity clauses.

Usage: Often followed by 'against' plus a gerund, or 'not to' plus an infinitive.

### 3. to order away

verb · CEFR B2

to tell someone they must leave a place or stay away from it.

For teachers: to advise or formally order someone to depart or to remain at a distance. Often used with 'off'.

- The security guard warned the teenagers off the private property.
- The farmer used a loud whistle to warn the hikers off his fields during the lambing season.

Usage: Frequently appears as the phrasal verb 'warn off'.

## Examples

- The signs warn drivers about the icy roads.
- The weather service issued a statement to warn residents that a heavy storm would arrive by midnight.
- Economists continue to warn that persistent inflation may eventually erode the purchasing power of middle-income households if wage growth remains stagnant.

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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.