1.Definition: (geometry) the interchangeability of the roles of points and planes in the theorems of projective geometry

Category: General

2.Definition: (physics) the property of matter and electromagnetic radiation that is characterized by the fact that some properties can be explained best by wave theory and others by particle theory

Category: General

3.Definition: being twofold; a classification into two opposed parts or subclasses

Related Noun(s):dichotomy

Category: General