proprietary

American  

[pruh-prahy-i-ter-ee] / prəˈpraɪ ɪˌtɛr i /

adjective

1. belonging to a proprietor.

2. being a proprietor; holding property.

   the proprietary class.

3. pertaining to property or ownership.

   proprietary wealth.

4. belonging or controlled as property.

5. (of a brand name, product, service, formula, etc.) protected by a patent, copyright, or trademark.

   proprietary drugs; a proprietary name; a proprietary logo; a proprietary blend of ingredients.

6. privately owned and operated for profit.

   proprietary hospitals.

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noun

• proprietaries
  plural

1. an owner or proprietor.

2. a body of proprietors.

3. American History. the grantee or owner, or one of the grantees or owners, of a proprietary colony.

4. ownership.

5. something owned, especially real estate.

6. a proprietary medicine.

7. Also called proprietary school.  a school organized as a profit-making venture primarily to teach vocational skills or self-improvement techniques.

proprietary British  

/ prəˈpraɪɪtərɪ, -trɪ /

adjective

1. of, relating to, or belonging to property or proprietors

2. privately owned and controlled

3. med of or denoting a drug or agent manufactured and distributed under a trade name Compare ethical

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noun

1. med a proprietary drug or agent

2. a proprietor or proprietors collectively

3. 1. right to property

   2. property owned

4. Also called: lord proprietary.  (in Colonial America) an owner, governor, or grantee of a proprietary colony

Other Word Forms

Derived Forms

• nonproprietary
  adjective
• proprietarily
  adverb

Inflected Forms

Nouns

• proprietaries
  plural

Etymology

Origin of proprietary

1400–50; late Middle English (noun) < Medieval Latin proprietārius owner, noun use of Late Latin: of an owner, of ownership. See propriety, -ary

Explanation

If you own something, especially something of value, then you have proprietary rights. The word is most often used in relation to new inventions or patents. Proprietary refers to property: things that are owned by individuals or businesses. People talk about proprietary drugs, proprietary software, and other things that can only be made and sold by those who discovered or created them. A proprietary claim is usually protected by trademark or copyright. When you say you have a proprietary right to something you're saying to everyone else: "Hands off! This is mine." Years ago, owners of small mom-and-pop stores were known as proprietors.

Example Sentences

See Examples For:

proprietary proprietaries

The telecom company is staking its future on open models, both to control token cost and protect its proprietary data.

From The Wall Street Journal ● Aug. 12, 2026

OpenAI and Anthropic don’t allow their proprietary AI software to be downloaded and used.

From Los Angeles Times ● Aug. 12, 2026

This has ample precedent in anti-money-laundering policy and trusted-access programs for advanced proprietary AI models.

From The Wall Street Journal ● Aug. 11, 2026

Utilizing proprietary inference simulators and coding benchmarks, SemiAnalysis arrives at $100 billion per GW of annual recurring revenue.

From MarketWatch ● Aug. 10, 2026

“Netscape helped to guarantee that these open protocols would not be proprietary by commercializing them for the public,” said Andreessen.

From "The World Is Flat" by Thomas L. Friedman

Though Evergreen bought Intermountain Aviation, one of Doole's CIA "proprietaries," in 1975, the company insists that it has had nothing further to do with the agency.

From Time Magazine Archive

With the spread of the influenza epidemic pernicious drug vendors cried new merits for their proprietaries.

From Time Magazine Archive

Learning at last that by obstinately contending for too much, they might possibly lose all, the proprietaries signified to doctor Franklin a willingness that their land should be taxed.

From The Life of Benjamin Franklin With Many Choice Anecdotes and admirable sayings of this great man never before published by any of his biographers by Mason Locke Weems

The disputes between the proprietaries and the Assembly, which for a time had subsided, were again revived.

From Memoirs of Benjamin Franklin; Written by Himself. [Vol. 1 of 2] With His Most Interesting Essays, Letters, and Miscellaneous Writings; Familiar, Moral, Political, Economical, and Philosophical by Benjamin Franklin

The governors received strict instructions to approve no bills for the raising of money for the purposes of defence, unless the estates of the proprietaries were specially exempted from the tax.

From Heroes of Science: Physicists by William Garnett

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