‖ avertin1|avɛrtɛ̃, ˈævətɪn| [Fr. (13th c. avertin, auvertin, 16th c. advertin), f.avertir to turn away, avert.] a. A vertiginous disease in sheep more usually called tournis. b. Mental disease which renders the patient obstinate and furious; crazy sullenness. 1864in Webster.