noun, plural pro·pri·e·tar·ies.

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
Related formspro·pri·e·tar·i·ly [pruh-prahy-i-tair-i-lee, -prahy-i-ter-] /prəˌpraɪ ɪˈtɛər ɪ li, -ˈpraɪ ɪˌtɛr-/, adverbnon·pro·pri·e·tar·y, adjective, noun, plural non·pro·pri·e·tar·ies. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for proprietary

Contemporary Examples of proprietary

Historical Examples of proprietary

  • He always said "your Bible," as if church members held a proprietary right.

    Tiverton Tales

    Alice Brown

  • "My daughters," said Olivo, turning to Casanova with a proprietary air.

    Casanova's Homecoming

    Arthur Schnitzler

  • It will readily be seen how advantageous these proprietary rights must have been to the wife.

    The Truth About Woman

    C. Gasquoine Hartley

  • The proprietary interest which she had always felt in him was more than ever hers now.

    The Portygee

    Joseph Crosby Lincoln

  • "I have a plan for her," said Harold, with a proprietary air.


    Alice Hegan Rice

British Dictionary definitions for proprietary



of, relating to, or belonging to property or proprietors
privately owned and controlled
med of or denoting a drug or agent manufactured and distributed under a trade nameCompare ethical (def. 3)

noun plural -taries

med a proprietary drug or agent
a proprietor or proprietors collectively
  1. right to property
  2. property owned
Also called: lord proprietary (in Colonial America) an owner, governor, or grantee of a proprietary colony
Derived Formsproprietarily, adverb

Word Origin for proprietary

C15: from Late Latin proprietārius an owner, from proprius one's own
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for proprietary

mid-15c., "possessing worldly goods in excess of a cleric's needs," from Medieval Latin proprietarius "owner of property," noun use of Late Latin adjective proprietarius "of a property holder," from Latin proprietas "owner" (see property). Meaning "held in private ownership" is first attested 1580s. The word was used earlier in English as a noun meaning "proprietor," also "worldly person" (c.1400), from a noun use in French and Medieval Latin.

Online Etymology Dictionary, © 2010 Douglas Harper

proprietary in Medicine




Exclusively owned, as of a hospital.
Owned by an individual or corporation under a trademark or patent, as of a drug.


A proprietary medicine.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.