smoke signal
noun
1- a column of smoke used as a way of conveying a message to a distant person（向远方传递信息的柱状）烟雾信号。
1.1
- figurative an indication of someone's intentions or views〈喻〉（传递某人意图、观点的）标记, 征兆：
a series of political smoke signals has aroused hopes for a fresh initiative on Northern Ireland.
一系列的政治征兆给人们带来解决北爱尔兰问题新举措的希望。