incoming (n.)youdaoicibaDictYouDict[incoming 词源字典]
late 14c., "action of coming in," from in + coming. As a present participle adjective, from 1753. Of game, from 1892; transferred in World War I to artillery; as a warning cry of incoming shellfire, it seems to date to the U.S. war in Vietnam (1968).[incoming etymology, incoming origin, 英语词源]