signallamp
nounUK /ˈsɪɡnəl læmp/
US /ˈsɪɡnəl læmp/
A signallamp is a light that tells people or cars what to do.
The red signallamp told the cars to stop.
OTHER MEANINGS
2. A lamp used to send messages by flashing or colored light.
The ship used a signallamp to talk to the shore.
3. A small light on a machine that shows if it is working.
The signallamp turned green when the machine was ready.
4. A light on a railway that tells trains when to go or stop.
The train waited until the signallamp changed.