signal

The word “signal” means something transmitted or displayed that conveys information, such as a light, sound, or electrical impulse. In plain terms, information sent through a channel (light, sound, radio waves), or, as a verb, to indicate something is happening.

“Signal” is pronounced SIHG-nuhl (/ˈsɪɡnəl/ in IPA).

Here is “signal” used in a sentence: “The ship sent a distress signal by radio.”

The opposite of “signal” — its antonyms — is noise.

Depending on how it is used, “signal” can be a noun, a verb and an adjective.

The word “signal” comes from Late Latin. From Old French segnal and Late Latin signalis, from Latin signum ("sign").

“Signal” is a fairly common word in modern English, usually learned at around the B1 level.

“Signal” has 4 distinct senses listed in this dictionary. The most common is: something transmitted or displayed that conveys information, such as a light, sound, or electrical impulse.

A sign carries meaning by pointing to or standing for something, often passively, like a road sign or a sign of illness. A signal is actively sent or displayed to convey specific information, frequently to prompt a response, such as a traffic light, an alarm, or a hand gesture.

Signals come in many forms. Visual signals use light or movement, like beacons and gestures; audible signals use sound, like sirens and bells; and electronic signals carry information as electrical or radio waves. Engineers also distinguish analog signals, which vary smoothly, from digital signals, which use discrete values.

Everyday examples include a red traffic light telling drivers to stop, a smoke alarm sounding, a referee's whistle, or the bars showing your phone's reception. Each one transmits or displays information meant to be noticed and understood, which is what makes it a signal rather than just an object.