cofounder

American

[koh-foun-der] / koʊˈfaʊn dər /

Or co-founder

noun

a person who founds or establishes something with another.

Etymology

Origin of cofounder

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

For one, even extremely capable, long-running agents can’t be held liable for their actions, said Box cofounder and CEO Aaron Levie, also speaking at the Summit.

From The Wall Street Journal • Mar. 27, 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

But Tesla is a tech stock, Future Fund cofounder Gary Black pointed out to Barron’s on Wednesday.

From Barron's • Feb. 4, 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

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023