canary

Definition

a small, brightly colored songbird with a melodious voice; a warning signal or indicator of danger.

中文 一种体型小、颜色鲜艳、鸣声优美的鸣鸟；危险的警告信号或指示。

Example

"They kept a canary in a cage because of its beautiful singing; miners once used canaries to detect gas leaks in tunnels."