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

plural

proprietaries

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

• nonproprietary adjective
• proprietarily adverb

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

Penney, Bloomingdale’s and proprietary stores in the same suburban shopping malls.

From The Wall Street Journal • Apr. 3, 2026

But the leak did reveal commercially sensitive information, including Anthropic’s proprietary techniques, tools and instructions for cajoling its AI models to work as coding agents.

From The Wall Street Journal • Apr. 1, 2026

One big advantage for the company is that it sits on a substantial amount of proprietary enterprise and consumer data, Lee said in a Tuesday note.

From MarketWatch • Apr. 1, 2026

Each provider uses proprietary protocols optimized for speed — Surfshark relies on WireGuard, while NordVPN uses NordLynx, a WireGuard-based protocol with additional privacy enhancements.

From Salon • Mar. 27, 2026

The dispute was over Morgan Stanley’s failure to deliver on its promise to spin Hubler’s proprietary trading group off into its own money management firm, of which he would own 50 percent.

From "The Big Short" by Michael Lewis

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