smoke signal

US /ˈsmoʊk ˌsɪɡ.nəl/
UK /ˈsmoʊk ˌsɪɡ.nəl/
"smoke signal" picture
1.

煙霧信號

a column of smoke used as a signal, especially one made by a fire on a mountain or hill to send a message

:
The stranded hikers sent up a smoke signal to alert rescuers.
被困的徒步旅行者發出煙霧信號以提醒救援人員。
In ancient times, smoke signals were a common way to communicate over long distances.
在古代,煙霧信號是遠距離通訊的常用方式。