signal
The word carries a sense of intentionality and brevity. It is not a full conversation, but a trigger or a marker designed to prompt a specific reaction or indicate a state of being. It functions as a bridge between an internal intention and an external action. In modern technical contexts, the word has shifted from human gestures to invisible data streams. While a physical signal is seen or heard, a technical signal is measured in strength and frequency, yet both serve the same purpose of transmitting a discrete piece of information from a sender to a receiver.
Countable when referring to a specific gesture or a distinct electronic transmission. Uncountable when referring to the general quality of a connection, such as having poor signal.
Meanings
A gesture, action, or sound used to convey information or a command.
"The referee gave the signal to start the game."
An electrical impulse or electromagnetic wave transmitted by a radio or electronic device.
"The television has a very weak signal in this room."