lightsignal
nounUK /ˈlaɪtˌsɪɡnəl/
US /ˈlaɪtˌsɪɡnəl/
A light that tells people or cars what to do.
The light signal turned red, so the cars stopped.
OTHER MEANINGS
2. A flashing light used to send a message.
The ship used a light signal to ask for help.
3. A light on a machine that shows if it is working.
The light signal on the printer turned green.
4. A light used to guide planes or boats.
Pilots look for the light signal near the runway.