"Mettlesome" is an adjective derived from the word mettle, meaning courage, spirit, or resilience. It describes someone or something that is full of energy, determination, and a strong sense of resolve. A mettlesome person is characterized by their bravery, enthusiasm, and the ability to confront challenges with vigor and perseverance. The term is often used to highlight someone’s spirited and adventurous nature, especially when faced with difficulties.

The word evokes an image of someone who is ready to face adversity head-on with a bold and dynamic attitude.