1. a signal or warning given in advance of the main signal, especially on a railway to alert a driver to prepare for the next signal ahead
Usage: chiefly British; railway/transportation term

1. to give a presignal; to signal in advance
Usage: chiefly British; railway/transportation term

Examples

• The presignal on the railway line warned the driver that the main signal ahead was red.
• Modern trains rely on presignals to ensure safe braking distances.
• The conductor presignaled the approach of the station.
• Presignals are essential safety features on busy rail networks.
• The driver checked the presignal before approaching the junction.