canary in a coal mine (English, noun)
expansion: canary in a coal mine (plural canaries in a coal mine or canaries in coal mines)
Senses:
glosses: Something whose sensitivity to adverse conditions makes it a useful early indicator of such conditions; something which warns of the coming of a greater danger or trouble by a deterioration in its health or welfare.
tags: idiomatic
Forms:
form: canaries in a coal mine
tags: plural
form: canaries in coal mines
tags: plural
form: canary in the coal mine
tags: alternative