A "formidable opponent" refers to an individual or group that poses a significant challenge or threat in a competitive situation. This term is often used in sports, politics, or business to describe someone who is highly skilled, powerful, or resourceful, making them difficult to defeat or overcome. In many contexts, facing a formidable opponent can motivate individuals or teams to improve their strategies and performance. For example, in boxing, a fighter may train harder when preparing to face a champion known for their strength and technique, highlighting the importance of preparation and resilience in competition.