# flag

/ˈfɫæɡ/ (US) · /flˈæɡ/ (UK)

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

## Senses

### 1. symbolic cloth

noun · CEFR A2

a piece of cloth with a special design that represents a country, group, or organization.

For teachers: a piece of fabric, usually rectangular, bearing a distinctive design used as a symbol, signaling device, or emblem of a nation or entity.

- The crowd waved their national flags during the opening ceremony of the games.
- The protocol for displaying the national flag requires it to be illuminated if flown after sunset.

### 2. a warning or indicator

noun · CEFR B1

a sign or signal that shows something needs attention or that a problem exists.

For teachers: a symbolic or digital indicator used to draw attention to a specific item, condition, or potential problem.

- The teacher put a red flag next to the student's name because he missed too many classes.
- The software developer added a flag to the code to alert the system whenever a user entered an invalid password.

### 3. to mark for attention

verb · CEFR B2

to mark something so that you or someone else will notice it later.

For teachers: to identify or mark an item for subsequent attention or treatment.

- I've flagged the most important emails so I can reply to them first tomorrow morning.
- The audit flagged several inconsistencies in the financial reports that required immediate clarification from the accounting department.

Usage: often used with 'up' in British English

### 4. to signal to stop

verb · CEFR B1

to wave at a driver to make them stop their vehicle.

For teachers: to signal a vehicle to stop, typically by waving one's hand or a physical flag.

- We had to flag down a taxi because it was raining and we didn't have an umbrella.
- The stranded motorist managed to flag down a passing truck just as his phone battery died.

Usage: commonly used as 'flag down'

### 5. to become tired

verb · CEFR C1 · Literary

to become tired, weak, or less interested in something.

For teachers: to decline in strength, vigor, or interest; to become languid or feeble.

- By the end of the long meeting, everyone's energy began to flag.
- Despite his initial enthusiasm for the project, his interest began to flag when the technical challenges became increasingly repetitive.

### 6. a flat stone

noun · CEFR C2 · Technical

a large, flat stone used for making paths or floors.

For teachers: a hard, flat stone used for paving slabs; a shortened form of 'flagstone'.

- The garden path was made of old grey flags that had grown moss over the years.
- The restoration committee insisted on sourcing authentic limestone flags to maintain the historical integrity of the cathedral floor.

### 7. a plant

noun · CEFR C2 · Technical

a type of plant with long, sword-shaped leaves, often a kind of iris.

For teachers: any of various plants with sword-shaped leaves, particularly those in the iris family.

- Yellow flags grew thickly along the edge of the river.
- The marshy banks were dominated by Iris pseudacorus, commonly known as the yellow flag, which provides essential habitat for local insects.

## Examples

- The national flag flies high above the government building.
- The referee raised his yellow flag to signal that a player was offside during the final minutes of the match.
- While the primary function of a flag is identification, it often serves as a potent emotional symbol capable of uniting a population or sparking intense political debate.

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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.