canary in a coal mine
Definition from Wiktionary, a free dictionary
Contents |
[edit] English
[edit] Etymology
An allusion to caged canaries mining workers would carry down into the tunnels with them. If poisonous gases such as methane or carbon monoxide leaked into the mine-shaft, the gases would kill the canary before killing the miners.
[edit] Noun
- A warning of danger or trouble yet to come.
