- Railway signal system - Signalling system - A signal telegraph; an apparatus for giving signals by
the disposition of lanterns, flags, oscillating arms, etc.
- Signalling system - An apparatus, or a process, for communicating
intelligence rapidly between distant points, especially by means of
preconcerted visible or audible signals representing words or ideas, or
by means of words and signs, transmitted by electrical action. - To convey or announce by telegraph.