duality

Plural: dualities

Noun

• The state of having two parts, aspects, or characteristics.
• being twofold; a classification into two opposed parts or subclasses
• (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
• (geometry) the interchangeability of the roles of points and planes in the theorems of projective geometry
• A classification into two subclasses or opposed parts.
• The interchangeability of points and planes.
• The mathematical equivalence of two seemingly different theoretical descriptions of a physical system.

Examples

• The DUALITY of offense and defense is crucial to mastering any word game like Scrabble.

Synonyms

dichotomy, wave-particle duality