do·​main | \dō-ˈmān, də-\

Definition of domain 

1 law

a : complete and absolute (see absolute sense 3) ownership of land our highways and roads have been in the domain of state and local governments— T. H. White b. 1915 — compare eminent domain

b : land so owned

2 : a territory over which dominion (see dominion sense 2) is exercised The forest is part of the king's domain.

3 : a region distinctively marked by some physical feature a domain of rushing streams, tall trees, and lakes

4 : a sphere (see sphere sense 4b) of knowledge, influence, or activity the domain of biblical scholarship outside the domain of city police

5 mathematics : the set of elements (see element sense 2b(3)) to which a mathematical or logical variable is limited specifically : the set on which a function (see function entry 1 sense 5a) is defined

6 physics : any of the small randomly oriented regions of uniform magnetization in a ferromagnetic substance

7 mathematics : integral domain

8 biology : the highest taxonomic category in biological classification ranking above the kingdom (see kingdom sense 4b)

9 biochemistry : any of the three-dimensional subunits of a protein that are formed by the folding of its linear peptide chain and that together make up its tertiary (see tertiary entry 1 sense 3c) structure

10 computers : a subdivision of the Internet consisting of computers or sites usually with a common purpose (such as providing commercial information) and denoted in Internet addresses by a unique abbreviation (such as com for commercial sites or gov for government sites) The domain ca is used for sites located in Canada. also : domain name Our domain is

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Examples of domain in a Sentence

The forest is part of the king's domain. My sister is the math expert in the family, but literature is my domain. Childcare is no longer solely a female domain.
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Recent Examples on the Web

As the planets in the sky move across these domains, different events — both tangible and emotional — are triggered. Aliza Kelly Faragher, Allure, "The 12 Astrological Houses: Interpreting Your Birth Chart Beyond the Zodiac," 6 Oct. 2018 Outside the elements is a paved path ringed with benches, intended to be the domain of the parents (who don’t like getting sand in their shoes). Alexandra Lange, Curbed, "How not to cheat children: Let them build their own playgrounds," 18 July 2018 Space is a warfighting domain just like the land the air and sea. Joshua Stewart,, "Trump suggests the military needs a new 'space force' military branch," 13 Mar. 2018 The secrecy enabled them to shut down the domains without spooking or tipping off bad actors. Elizabeth Dwoskin, The Seattle Times, "Microsoft CEO Nadella welcomes scrutiny that has roiled tech industry. Easy for him to say," 9 Oct. 2018 So thinking about the domestic spaces is absolutely a way to think about historically female domains. Joanna Scutts, Curbed, "At home with our favorite characters," 9 Oct. 2018 The domain for Playboy magazine founder Hugh Hefner and his bunnies was based in the Windy City from 1959 to 1974. Stephanie Nolasco, Fox News, "Hugh Hefner's daughter Christie opens up about keeping Playboy founder's legacy alive," 27 Sep. 2018 The domain was registered through Namecheap on August 13, using a registration privacy protection company in Panama. Sean Gallagher, Ars Technica, "NewEgg cracked in breach, hosted card-stealing code within its own checkout," 19 Sep. 2018 Turns out that Matt Embrescia and Second Generation owned a top-level domain (TLP) for .jobs. Michael C. Dealoia,, "Cleveland duo creates platform, Innovation Fund gives grants: Tech Czar Talk," 11 Feb. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'domain.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of domain

15th century, in the meaning defined at sense 1a

History and Etymology for domain

alteration of Middle English demayne, from Anglo-French demeine, from Latin dominium, from dominus — see dominate

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Dictionary Entries near domain







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1 Dec 2018

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Time Traveler for domain

The first known use of domain was in the 15th century

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More Definitions for domain



English Language Learners Definition of domain

: the land that a ruler or a government controls

: an area of knowledge or activity

computers : a section of the Internet that is made up of computers or sites that are related in some way (such as by use or source)


do·​main | \dō-ˈmān \

Kids Definition of domain

1 : land under the control of a ruler or a government

2 : a field of knowledge or activity the domain of science


do·​main | \dō-ˈmān, də- \

Medical Definition of domain 

1 : any of the three-dimensional subunits of a protein that together make up its tertiary structure, that are formed by folding its linear peptide chain, and that are variously considered to be the basic units of protein structure, function, and evolution immunoglobulin light chains have two domains and heavy chains have four or five domains, depending on classJournal of the American Medical Association

2 : the highest taxonomic category in biological classification ranking above the kingdom

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More from Merriam-Webster on domain

Rhyming Dictionary: Words that rhyme with domain

Thesaurus: All synonyms and antonyms for domain

Spanish Central: Translation of domain

Nglish: Translation of domain for Spanish Speakers

Britannica English: Translation of domain for Arabic Speakers Encyclopedia article about domain

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a soft lustrous wool fabric with mohair

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