sign

/saɪn/

a perceptible indication of something not immediately apparent (as a visible clue that something has happened)

中文释义：迹象；征兆；标志

Dark clouds are often a sign of approaching rain.

乌云通常是即将下雨的征兆。

There was no sign of life in the abandoned house.

那座废弃的房子里没有生命迹象。