Any signal sent by semaphore.

(rail transport) Synonym of signal box

(rail transport, British spelling) A rail safety system installed in the driving cab of a train, which gives information to the train driver on track status and condition.

simple past tense and past participle of signal boost

present participle of signal boost

plural of signal boost

Third-person singular simple present indicative form of signal boost

(rail transport) Synonym of starting signal.

(rail transport) A railway signal controlling the starting of trains from a station or some other location, nowadays usually a colour-light signal. / (sports) A signal to begin a race.

(rail transport) A railway signal controlling entry to the next section of line. Originally it meant a signal governing entry into a station.