topological space: Meaning and Definition of

topolog'ical space'

Pronunciation: [key]
— Math. Math.
  1. a set with a collection of subsets or open sets satisfying the properties that the union of open sets is an open set, the intersection of two open sets is an open set, and the given set and the empty set are open sets.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.