n.1. the act of turning the forearm so that the palm faces upward, or the condition resulting from this action. 2. the act of turning the foot so that the sole faces inward and the medial (inner) margin is raised (as in walking on the outside of one’s feet), or the condition resulting from such an action. 3. the state or condition of being supine (see posture). Compare pronation. —supinatevb.