1.especially British EnglishBrETTT someone whose job is to control railwaysignals 〔鐵路的〕信號員,信號工
2.PMA (also signaller British English)PMN a member of the army or navy who is trained to send and receive signals 〔陸軍或海軍的〕信號手,信號兵
Examples from the Corpus
signalman• After his demobilisation from the Navy he was accepted by the railway authorities to train as a signalman.• Never again would a signalman give the signal that all was clear.• A signalman passed by, motioning with his greenflag.• A factor in this was excessiveovertime with many signalmen working 7 days a week for a month.• All the same, signalmen can be a fund of unexpectedtales and it is always interesting to hear their stories.• The narrator, returning to the box shortly afterwards, finds that the signalman has been run over by a train.• The signalman in his isolated box tells the narrator of an apparition he has now seen three times.• The conditions under which signalmen had to work can only be imagined.