domain

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noun do·main \dō-ˈmān, də-\

Definition of domain

  1. 1 law a :  complete and absolute (see absolute 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 domainb :  land so owned

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

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

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

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

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

  7. 7 mathematics :  integral domain

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

  9. 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 1tertiary 3c) structure

  10. 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 Merriam-Webster.com.

Examples of domain in a Sentence

  1. The forest is part of the king's domain.

  2. My sister is the math expert in the family, but literature is my domain.

  3. Childcare is no longer solely a female domain.

Recent Examples of domain from the Web

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.

Origin and Etymology of domain

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



DOMAIN Defined for English Language Learners

domain

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noun

Definition of domain for English Language Learners

  • : 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)


DOMAIN Defined for Kids

domain

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noun do·main \dō-ˈmān\

Definition of domain for Students

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

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

  3. 3 :  domain name

Word Root of domain

The Latin word dominus, meaning “master,” gives us the root domin. Words from the Latin dominus have something to do with being another's master. To dominate is to have power and control over as if being someone's master. A domain, or land under the control of a government, is a land with a particular master or ruler. Dominion is controlling power, similar to the power of a master over others.


Medical Dictionary

domain

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noun do·main \dō-ˈmān, də-\

Medical Definition of domain

  1. 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 class—Journal of the American Medical Association

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



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