1. The act of turning or whirling, as around a fixed center; a circular or spiral motion; motion about an axis; rotation; revolution. The gyrations of an ascending balloon. (De Quincey) If a burning coal be nimbly moved round in a circle, with gyrations continually repeated, the whole circle will appear like fire. (Sir i. Newton)
2. (Science: zoology) One of the whorls of a spiral univalve shell. Center of gyration.
3. (Science: physics) radius of gyration the distance between the axis of a rotating body and its center of gyration.