This verb means to enslave, subjugate, or bring under strict discipline—literally to treat something as a slave. Paul uses it in 1 Corinthians 9:27 describing his self-discipline: 'I discipline my body and bring it into subjection.' The image is of an athlete or fighter exercising rigorous control over physical impulses to achieve a goal. Classical Greek used it for reducing someone to slavery or exercising harsh control. Paul applies it to voluntary self-mastery—treating his body as a slave to ensure his ministry's effectiveness.