Topology

noun

1. A branch of mathematics studying those properties of a geometric figure or solid that are not changed by stretching, bending and similar homeomorphisms.
2. A collection τ of subsets of a set X such that the empty set and X are both members of τ, and τ is closed under finitary intersections and arbitrary unions.
3. The anatomical structure of part of the body.
4. The arrangement of nodes in a communications network.
5. The properties of a particular technological embodiment that are not affected by differences in the physical layout or form of its application.