cofounder

American  

[koh-foun-der] / koʊˈfaʊn dər /

Or co-founder

noun

1. a person who founds or establishes something with another.

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Etymology

Origin of cofounder

First recorded in 1595–1605; co- + founder ¹

Example Sentences

OpenAI, CEO Sam Altman and Microsoft are listed as defendants in former OpenAI cofounder Elon Musk’s lawsuit over OpenAI’s creation of a “capped profit” subsidiary in 2019.

From MarketWatch • Apr. 27, 2026

Designer Rob Janoff said that Apple cofounder Steve Jobs gave him one terse instruction when he commissioned a new logo in January 1977: "don't make it cute".

From Barron's • Mar. 29, 2026

Why Palantir cofounder and CEO Alex Karp views working with Western militaries not just as a business opportunity, but as a higher calling.

From Slate • Mar. 22, 2026

The technology can reduce costs for utilities that typically rely on workers to inspect vast numbers of assets, while also improving safety, said Jack Curtis, a cofounder and the company’s chief commercial officer.

From The Wall Street Journal • Feb. 9, 2026

The sunken ship lay on the ocean floor for more than seventy-two years until, on August 19, 2017, a team headed by Microsoft cofounder Paul Allen discovered it lying some 18,000 feet beneath the sea.

From "Shipwrecked!" by Martin W. Sandler