Beard the lion in his den
Beard the lion in his den
to have this courage to visit and oppose a person in authority on his own grounds, to confront risk and danger by accosting someone in power, challenge someone, oppose, accost, detain, defy, face up to, object to, dispute:
Discontented with her low salary, the audacious new employee went toward the manager’s office to beard the lion in his den and ask for a rise in her remuneration.
