Origin: Latin suffix -al
Signal has 9 different meanings across 3 categories:
any incitement to action
"he awaited the signal to start"
"the victory was a signal for wild celebration"
an electric quantity (voltage or current or field strength) whose modulation represents coded information about the source from which it comes
"The radar system detected a faint signal indicating that the distant aircraft was approaching at high speed."
A sequence of states representing an encoded message in a communication channel.
"The receiver successfully decoded the data stream after correcting errors in the noisy signal transmitted across the fiber optic cable."
In plain English: A signal is a sign or message sent to show that something is happening or to get someone's attention.
"The traffic light turned green to signal that it was safe to drive forward."
To indicate; to convey or communicate by a signal.
"The driver tapped his steering wheel to signal that he was ready to merge into traffic."
In plain English: To signal means to send a message or show something to someone else, usually by using hand gestures or lights.
"She signaled him to stop at the red light."
Standing above others in rank, importance, or achievement.
"The veteran captain was a true signal to the young recruits, commanding respect through years of unchallenged skill and leadership."
In plain English: When something is described as a signal, it means it is clearly noticeable and easy to see or hear.
"The signal light on the dashboard blinked red to warn the driver."
Usage: Use signal as an adjective to describe someone who stands out prominently due to high rank, great importance, or exceptional achievement. It is often interchangeable with words like distinguished or prominent, but carries a stronger sense of being exemplary or leading the way in a specific field.
The word "signal" comes from Old French and Medieval Latin, originally referring to an object used for communication. It entered English in the early 19th century as a shortened form of the verb "signalize," which had been in use since the mid-1600s.