Definitions

1. noun

a sheep that shows the way for a flock, typically one with a bell around its neck, used metaphorically to describe a person or thing that indicates the direction or trend of a group or movement.

“The politician’s proposal was seen as a bellwether for the party’s future direction.”

2. verb

to serve as a bellwether for (a person or thing)

“The company’s new policy will bellwether the industry’s shift towards sustainability.”