<p><strong>Noun:</strong></p><ul><li>Veterinary Pathology. Also called canine distemper: an infectious disease chiefly of young dogs, caused by an unidentified virus and characterized by lethargy, fever, catarrh, photophobia, and vomiting.</li><li>Also called colt distemper: an infectious disease of horses, caused by the bacillus <em>Streptococcus equi</em> and characterized by catarrh of the upper air passages and the formation of pus in the submaxillary and other lymphatic glands.</li><li>Also called cat distemper: a usually fatal viral disease of cats, characterized by fever, vomiting, and diarrhea, leading to severe dehydration.</li><li>a deranged condition of mind or body; a disorder or disease: a feverish distemper.</li><li>disorder or disturbance, especially of a political nature.</li></ul><p><strong>Verb:</strong></p><ul><li>(used with object) Obsolete: to derange physically or mentally.</li></ul>