# signal

/ˈsɪɡnəɫ/ (US) · /sˈɪɡnəl/ (UK)

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

## Senses

### 1. a sign or instruction

noun · CEFR B1

a sound, action, or light that gives a message or a command.

For teachers: a sign, gesture, or device used to convey information, give notice of an occurrence, or initiate a concerted action.

- The referee gave the signal for the game to begin.
- The flare served as a prearranged signal for the ground troops to commence their advance toward the perimeter.

### 2. electronic transmission

noun · CEFR B1

the electronic waves that carry information to your phone, TV, or radio.

For teachers: an electromagnetic impulse or variable voltage that transmits data, audio, or video across a communication channel.

- I'm sorry, I can't hear you because my phone signal is very weak here.
- Engineers worked to filter out the background noise to ensure the satellite signal remained clear during the atmospheric disturbance.

### 3. traffic light

noun · CEFR B1

a light used to direct traffic on a road or railway.

For teachers: a technical device, such as a semaphore or light, used to regulate the movement of vehicles or trains.

- The driver stopped because the signal turned red.
- The automated railway signal failed during the storm, forcing all incoming trains to halt outside the station for safety.

### 4. to give a sign

verb · CEFR B1

to show or tell something by making a movement or using a light.

For teachers: to communicate or indicate information through a non-verbal sign or electronic transmission.

- She signalled to the waiter that she wanted the bill.
- The CEO's speech was intended to signal a shift in the company's long-term environmental strategy to the shareholders.

### 5. notable or important

adjective · CEFR C2 · Formal · Literary

very important or easy to notice.

For teachers: distinguished from others by being particularly important, notable, or significant.

- The new law was a signal victory for the rights of workers.
- The signing of the peace treaty was regarded as a signal achievement in the diplomat's long and distinguished career.

## Examples

- The phone has a very weak signal in this room.
- The router converts the incoming internet signal into a wireless connection for all the devices in the house.
- Engineers must account for signal interference when designing high-density circuits, as overlapping electromagnetic fields can corrupt the data being transmitted between components.

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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.