complex /kom″pleks, kəmpleks′/ [L, complexus, an embrace] , 1. a group of items, such as chemical molecules, that are related in structure or function as are the iron and protein portions of hemoglobin or the cobalt and protein portions of vitamin B12. 2. a combination of signs and symptoms of disease that forms a syndrome. 3. (in psychology) a group of associated ideas with strong emotional overtones that affect a person’s attitudes toward a specific subject.
