domain

noun17

1. •
   A geographic area owned or controlled by a single person or organization.

   • The king ruled his domain harshly.
2. •
   A field or sphere of activity, influence or expertise.

   • Dealing with complaints isn't really my domain: get in touch with customer services.
   • His domain is English history.
3. •
   A group of related items, topics, or subjects.
4. •
   A collection of information having to do with a domain, the computers named in the domain, and the network on which the computers named in the domain reside.
5. •
   The collection of computers identified by a domain's domain names.
6. •
   (Internet) Any DNS domain name, particularly one which has been delegated and has become representative of the delegated domain name and its subdomains.

   • Every name in the DNS tree is a domain, even if it is terminal, that is, has no subdomains. — 2000
7. •
   (Internet) A collection of DNS or DNS-like domain names consisting of a delegated domain name and all its subdomains.
8. •
   The set of input (argument) values for which a function is defined.
9. •
   The set A; The subset of A consisting of elements a of A such that there exists an element b in B with (a,b) in R.
10. •
    The highest rank in the classification of organisms, above kingdom; in the three-domain system, one of the taxa Bacteria, Archaea, or Eukaryota.
11. •
    A folded section of a protein molecule that has a discrete function; the equivalent section of a chromosome.
12. •
    A small region of a magnetic material with a consistent magnetization direction.
13. •
    Such a region used as a data storage element in a bubble memory.
14. •
    An area of more or less uniform mineralization.
15. •
    A form of technical metadata that represent the type of a data item, its characteristics, name, and usage.

    • A characteristic of a field. A data domain specifies a data type and applies the minimum and maximum values allowed and other constraints. — 2013
16. •
    An open and connected set in some topology. For example, the interval (0,1) as a subset of the real numbers.
17. •
    A ring with no zero divisors; that is, in which no product of nonzero elements is zero.