1. Rotation of the forearm and hand so that the palm faces forward or upward and the radius lies parallel to the ulna; also, a corresponding movement of the foot and leg.
2. The act of assuming the supine position, or the state of being supine.

Applied to the hand, the act of turning the palm forward (anteriorly) or upward, performed by lateral rotation of the forearm.

Applied to the foot, it generally implies movements resulting in raising of the medial margin of the foot, hence of the longitudinal arch.