Enlist/ɪnˈlɪst/ Definition 1 of 2Pro Tip 1/3Military Context Enlist often refers to joining military services and involves commitment. After college, Mark decided to enlist in the Marine Corps. Pro Tip 2/3Voluntary Action Enlisting is generally a personal choice, indicating that someone willingly joins up. She chose to enlist rather than being drafted. Pro Tip 3/3Long-term Commitment Enlisting usually requires a multi-year commitment, especially in the military. By enlisting, he agreed to serve for four years.