signal
//ˈsɪɡnəl//
Noun
A gesture, action, or sound that conveys information or instructions
She gave me a signal to start speaking.
An electrical impulse or radio wave transmitted or received
The phone receives a strong signal in this area.
A device that uses lights or mechanical arms to give instructions, especially to control traffic or trains
The traffic signal turned red, so all the cars stopped.
An indication or sign of something, especially of a future event or condition
The rise in unemployment is a signal of economic trouble.
Synonym
Verb
To make a gesture or sound to convey information or instructions to someone
She signaled to the waiter to bring the check.
To indicate or be evidence of something
Dark clouds signal that rain is coming.
Adjective
Striking or remarkable in quality; outstanding
The team achieved a signal victory in the championship.