phase space

Short definition from Wiktionary

Noun

1. 1
   Given a (dynamical) system, any topological space such that every point in the space's underlying set uniquely represents a state of the system and every possible state is represented by some point;
2. 2
   Given a (dynamical) system, any topological space such that every point in the space's underlying set uniquely represents a state of the system and every possible state is represented by some point; (less formally) the underlying set of such a topological space: the underlying set of such a topological space.