Any signal sent by semaphore.

plural of semaphore signal

(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

plural of danger-signal

(rail transport) Synonym of starting signal.