Double-checking I picked a good word with Domain: I did.

DOMAIN [via Wikipedia]

Mathematics-

-* Domain of a function, the set of input values for which the function is defined

-* Domain of discourse, the set of entities over which logic variables may range

-* Domain of an algebraic structure, the set on which the algebraic structure is defined

-* Domain (mathematical analysis), an open connected set

-* Domain theory, studying certain kinds of partially ordered sets

-* Domain (ring theory), a nontrivial ring without left or right zero divisors

–* Integral domain, a non-trivial commutative ring without zero divisors

—* Atomic domain, an integral domain in which every non-zero non-unit is a finite product of irreducible elements

—* Bezout domain, an integral domain in which the sum of two principal ideals is again a principal ideal

—* Euclidean domain, an integral domain which allows a suitable generalization of the Euclidean algorithm

—* Dedekind domain, an integral domain in which every nonzero proper ideal factors into a product of prime ideals

—* GCD domain, an integral domain in which every two non-zero elements have a greatest common divisor

—* Principal ideal domain, an integral domain in which every ideal is principal

—* Unique factorization domain, an integral domain in which every non-zero element can be written as a product of irreducible elements in essentially a unique way

-* Frequency domain, the analysis of mathematical functions with respect to frequency, rather than time

-* Fundamental domain, a symmetry group of an object is a part or pattern, as small or irredundant as possible, which determines the whole object based on the symmetry

-* Time domain, the analysis of mathematical functions with respect to time

Science-

-* Domain (biology), a taxonomic subdivision larger than a kingdom

-* High-field domain (physics) in semiconductors, also called Boer domain

-* Protein domain (biology), a part of a protein that can exist independently of the rest of the protein chain

-* Magnetic domain (physics), a region within a magnetic material which has uniform magnetization

-* Social domain, a concept in sociology

-* Domain of discourse, the collection of entities of interest in logical analysis

Information technology-

-* Administrative domain

-* Broadcast domain, in computer networking, a group of special-purpose addresses to receive network announcements

-* Collision domain

-* Domain (software engineering), a field of study that defines a set of common requirements, terminology, and functionality for any software program constructed to solve a problem in a given field

–* Application domain, a mechanism used within a Common Language Infrastructure to isolate executed software applications from one another

–* Programming domain, a set of programming languages or programming environments that were engineered specifically for a particular domain (software engineering)

-* Network domain, a named grouping of hosts and servers with managed login, access to resources, and permissions.

–* Domain name, a label that identifies a realm of administrative autonomy, authority, or control within the Internet

Other uses-

-* Territory (subdivision), a non-sovereign geographic area which has come under the authority of another government

-* Demesne, in English common law and other Medieval European contexts, lands directly managed by their holder rather than being delegated to subordinate managers

-* Domain, or Battlespace, a concept in military operations dividing operating environments into defined components: air, land, maritime, space, cyberspace, information, and electromagnetic spectrum