dysthymia, dysthymic 1. A mood disorder characterized by mild depression. 2. A type of depression involving long-term, chronic symptoms that do not disable a person, but which keeps one from functioning fully or from feeling at one's best. 3. Dysthymia is less severe than depression and what is considered a major depression; however, people with ... Found on http://www.wordinfo.info/words/index/info/view_unit/2147/