noun
Imperial train; royal train
A train used by the Emperor or other members of the Imperial family. The term is specific to Japan's Imperial Household.
お召し列車が駅を通過するとき、多くの人が見送った。
Many people saw off the Imperial train as it passed through the station.
From お召し (o-meshi, honorific for 'summon' or 'call') + 列車 (ressha, 'train'), literally 'honorable summoning train', referring to a train used by the Emperor.