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signal
Definition
A signal is a change in something that can be used to communicate information. For example, a change in the brightness of a light can be a signal that it is time to wake up.
Signals can be used to communicate between people, animals, and machines. They can also be used to control devices and to transmit data.
There are many different types of signals, including:
- Electrical signals: Electrical signals are used to transmit data in computers and other electronic devices.
- Sound signals: Sound signals are used to communicate between people and animals.
- Light signals: Light signals are used to communicate between ships, aeroplanes, and other vehicles.
- Chemical signals: Chemical signals are used to communicate between cells in the body.
How can the word be used?
The train driver gave a signal to the engineer.
Different forms of the word
Noun:
- a gesture, sound, or other means of conveying information or instructions.
- a distinctive mark or sign.
- a sudden change in the behaviour of an animal or plant, indicating the presence of something.
Verb:
- to give a signal to someone.
- to make a gesture or sound to convey information or instructions.
- to indicate the presence of something by a sudden change in behaviour.
Etymology
The word "signal" comes from the Latin word "signum", which means "mark" or "sign".
The first recorded use of the word "signal" in English was in the 14th century.
The word "signal" is a Latin word, and it is related to the English word "signature".
Question
What is a signal?