I. ˈ ̷ ̷| ̷ ̷ ̷ ̷ noun
Etymology: Middle English, from belle bell + wether
1. : a belled wether or sheep
2. : one that takes the lead or initiative : leader
distinguished for his outstanding work as a bellwether bomber pilot — R.G.Hubler & J.A.DeChant
California, traditional bellwether of the canning industry — Wall Street Journal
II. noun
: an indicator of trends