do·​main | \ dō-ˈmān How to pronounce domain (audio) , 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 Once the domain of Richard Simmons bouncing around in garish outfits, video exercise has been taken over by serious fitness buffs who are streaming hard-core workouts. Jeff Strickler, Star Tribune, "Video workouts get a second wind thanks to COVID," 4 Sep. 2020 The directive, the fifth from the National Space Council during the Trump administration, comes as space is increasingly viewed as a war-fighting domain. Washington Post, "Trump’s White House pushes measure to harden satellites against cyber threats," 4 Sep. 2020 According to the Chagossians’ claim, .io domain registrations bring in fees of $10 million each year, and the ccTLD has an overall value of around $50 million. David Meyer, Fortune, "‘Colonialism’ and crypto claims: Why the .io domain name extension faces an uncertain future," 31 Aug. 2020 WordPress the company also sells domain names and an array of personal, business, and enterprise Web hosting packages. Kate Cox, Ars Technica, "Apple apologizes to WordPress, no longer requires free app to add purchases," 24 Aug. 2020 In the paper, the researchers propose that the artifacts were ornamental tablets or plaquettes created by a latter-day Ice Age people called the Magdalenians whose domain extended across Europe, reports the Irish News. Alex Fox, Smithsonian Magazine, "Engraved Stones Found to be the Earliest Known Human Art in the British Isles," 21 Aug. 2020 The Space Force envisions itself as holding the ultimate high ground—the domain that looks down upon all over domains. Kyle Mizokami, Popular Mechanics, "The Space Force Spells Out What 'Spacepower' Is All About," 17 Aug. 2020 The most distinctive tactic that CyCraft found the hackers using repeatedly in the victims' networks, however, was a technique to manipulate domain controllers, the powerful servers that set the rules for access in large networks. Andy Greenberg, Wired, "Chinese Hackers Have Pillaged Taiwan's Semiconductor Industry," 6 Aug. 2020 The toothfish is an even trickier case because so much of its population lives outside the domain of any country. Tristram Korten, Smithsonian Magazine, "The Hunt for the Modern-Day Pirates Who Steal Millions of Tons of Fish From the Seas," 21 Aug. 2020

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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Time Traveler for domain

Time Traveler

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

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Last Updated

7 Sep 2020

Cite this Entry

“Domain.” Dictionary, Merriam-Webster, Accessed 18 Sep. 2020.

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More Definitions for domain


How to pronounce domain (audio)

English Language Learners Definition of domain

: the land that a ruler or a government controls
: an area of knowledge or activity
: 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 How to pronounce domain (audio) \

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- How to pronounce domain (audio) \

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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