Divided into several (usually three or more) groups or subsets; (in later use) involving or relating to a categorical variable that can take any of three or more values. rare before 20th century.
2Characterized by or designating branch points or nodes from which three or more branches diverge. Biology. Of physical structures.
3Of diagrams and mental constructs.
Mid 19th century; earliest use found in William S. Hamilton (1788–1856), philosopher. From poly- + ancient Greek -τόμος + -ous.