Lewis & Short

vŏlūbĭlĭtas, ātis, f. [volubilis], a rapid whirling motion.

  1. I. Lit.: mundi, Cic. N. D. 2, 19, 49; id. Fat. 19, 43; id. Univ. 10; Ov. F. 6, 271; App. Asclep. p. 100, 41.
  2. II. Transf., roundness, round form: fracta capitis latissima, Ov. M. 12, 434.
  3. III. Trop.
    1. A. Of speech, rapidity, fluency, volubility: linguae volubilitas, Cic. Planc. 25, 62: flumen aliis verborum volubilitasque cordi est, id. Or. 16, 53; id. de Or. 1, 5, 17: nimia vocis, Quint. 11, 3, 52 (opp. tarditas); 10, 1, 8; Plin. Ep. 5, 20, 4.
    2. B. Of fate, changeableness, mutability: quod temere fit caeco casu et volubilitate fortunae, Cic. Div. 2, 6, 15; Plin. 37, 1, 2, § 3.