1
a
of software : having the source code freely available for possible modification and redistribution
an open-source operating system
b
: of, relating to, or promoting open-source software
the open-source movement/community
Instead, they opted for the open-source model, in which computer code is openly shared, allowing programmers to modify, improve and fix the software.—Steve Lohr
2
a
: publicly available for use by the community at large
open-source images
The team uses open-source materials such as obituaries in local newspapers and cemetery visits for its count.—Brendan Hoffman
b
: relating to or utilizing information that is publicly available
an open-source analysis
Since the advent of the internet, social media and smartphones, open-source intelligence has undergone a revolution as people willingly and publicly post vast amounts of information online. Actors outside of the traditional intelligence community have begun to take notice.—Nick Waters

Examples of open-source in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Most web pages run using an open-source programming language called PHP. — Emily Forlini, Fortune, 21 Oct. 2026 DeepSeek is one of China's leading and best-known AI companies and its open-source models are widely available in countries including the United States. — ABC News, 20 Oct. 2026 Policy engines such as Open Policy Agent and AWS’s open-source Cedar can evaluate each request against policy at runtime. — Julian Durand, Forbes.com, 20 Oct. 2026 DeepSeek launched a preview of its V4 model, expanding its open-source AI lineup on April 24. — Jenny Lee,kai Nicol-Schwarz, CNBC, 20 Oct. 2026 See All Example Sentences for open-source

Word History

First Known Use

1956, in the meaning defined at sense 2

Time Traveler
The first known use of open-source was in 1956

Cite this Entry

“Open-source.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/open-source. Accessed 23 Oct. 2026.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster