clarion call
clar‧i‧on call /ˈklæriən ˌkɔːl $ -ˌkɒːl/
noun [countable] formal
This election is a clarion call for our country to face the challenges ahead.
clar‧i‧on call /ˈklæriən ˌkɔːl $ -ˌkɒːl/
noun [countable] formal Date: 1800-1900
Origin: clarion type of trumpet (used for battle signals) 1300-1400 Medieval Latin clario, from Latin clarus; ⇨ clear1
a strong and direct request for people to do something:Origin: clarion type of trumpet (used for battle signals) 1300-1400 Medieval Latin clario, from Latin clarus; ⇨ clear1