canary in a coal mine

idiomPart ofcanary

canary in a coal mine — idiom

1. a person, thing, or situation that serves as an early warning of danger or probl

1.idiom
Definition

a person, thing, or situation that serves as an early warning of danger or problems that are about to affect a larger group

Example

The sudden drop in the river's fish population was a canary in a coal mine for the region's water quality.

Rising costs in the housing market are often a canary in a coal mine for the broader economy.