domain

plural domains

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

   The king ruled his domain harshly.

   3 more examples

   Bears and other ferocious beasts resented man's intrusion into their domain; so, too, did the Blackfoot Indians and other tribes, whose savage hostility was a constant menace to the lives of the toiling engineers.

   1954 February, Trevor Holloway, “Canada's Transcontinental Routes”, in Railway Magazine, page 128

   Farmers account for just 1.5% of the British population, but the size of their domain – 71% of the country’s surface area is classified as farmland – has given them power over the public imagination.

   2020 February 25, Christopher de Bellaigue, “The end of farming?”, in The Guardian

   A blinded hermit in oblivion, disgraced Like Odysseus lost in Poseidon's endless domain In a realm devoid ov solace, I roam

   2022, “Ov My Herculean Exile”, in Nergal, Tomasz Wróblewski (lyrics), Behemoth (music), Opvs Contra Natvram, performed by Behemoth

   Synonyms: demesne

2. A field or sphere of activity, influence or expertise.

   His domain is English history.

   2 more examples

   Dealing with complaints isn't really my domain: get in touch with customer services.

   When examining studies that assess independent living and social skills—key areas of focus in adulthood for individuals with ASD—it is observed that most research evaluates only one of these domains, either activities of daily living or social functioning.

   2025 August 13, Müjdat Erarkadaş, Kübra Özmeral Erarkadaş, Şahika Gülen Şişmanlar, “Autism Spectrum Disorder Beyond Childhood: A Comprehensive Assessment of Activities of Daily Living and Social Functioning in Turkish Adults.”, in Journal of Autism and Developmental Disorders, →DOI

3. A group of related items, topics, or subjects.

   1 more example

   Some of the most beautiful and thus appealing physical theories, including quantum electrodynamics and quantum gravity, have been dogged for decades by infinities that erupt when theorists try to prod their calculations into new domains. Getting rid of these nagging infinities has probably occupied far more effort than was spent in originating the theories.

   2012 January 28, Michael Riordan, “Tackling Infinity”, in American Scientist, volume 100, number 1, archived from the original on 30 Apr 2013, page 86

4. mathematicsThe set of input (argument) values for which a function is defined.
   1. broadlymathematicsThe 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.
5. mathematicsA ring with no zero divisors; that is, in which no product of nonzero elements is zero.
6. mathematical analysisAn open and connected set in some topology. For example, the interval (0,1) as a subset of the real numbers.
7. InternetcomputingAny DNS domain name, particularly one which has been delegated and has become representative of the delegated domain name and its subdomains.

   2000, BIND 9 Administrator Reference Manual (9.3.2), Internet Software Consortium https://web.archive.org/web/20060619063455/http://www.bind9.net/manual/bind/9.3.2/Bv9ARM.ch01.html Every name in the DNS tree is a domain, even if it is terminal, that is, has no subdomains.

8. InternetcomputingA collection of DNS or DNS-like domain names consisting of a delegated domain name and all its subdomains.

   Synonyms: domain name, hostname

9. computingA 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.
10. computingThe collection of computers identified by a domain's domain names.
11. natural sciencesA small region of a magnetic material with a consistent magnetization direction.
12. computingSuch a region used as a data storage element in a bubble memory.
13. data processingA 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.

    a. 2013, IBM, “IBM Terminology - terms D”, in 'IBM Software|Globalization|Terminology', retrieved 29 Dec 2013

14. biologyThe highest rank in the classification of organisms, above kingdom; in the three-domain system, one of the taxa Bacteria, Archaea, or Eukaryota.

    Synonyms: dominium

15. biochemistryA folded section of a protein molecule that has a discrete function; the equivalent section of a chromosome.
16. geographyAn area of more or less uniform mineralization.