foundational

adjective

foun·​da·​tion·​al fau̇n-ˈdā-sh(ə-)nəl 

: of, relating to, or forming or serving as a base or foundation : fundamental

foundational principles/doctrines

These foundational volumes proved to be, each in its own way, enabling gestures for the growth of sophisticated theories and critical practices in African, Caribbean, and African American literatures.

—Henry Louis Gates, Jr.

Property was, in a sense, foundational to culture, since English political economy rested on the private ownership of land, and the political economy, in turn, largely structured social relations.

—Jill Lepore

Philosophy is a foundational discipline. Not only does it do the spadework that makes the construction of other disciplines possible; it also pays constant attention to the foundations of those disciplines as they are practiced.

—Cognitive Science

foundationally adverb

Examples of foundational in a Sentence

Recent Examples on the Web

Speakers ranged from foundational AI researchers and university leaders to executives building large-scale infrastructure and next-generation systems. —John Werner, Forbes.com, 24 Jan. 2026

The Future of Storage Starts Now Looking ahead, long-duration battery energy storage will play a foundational role in building resilient, low-carbon power systems worldwide. —CBS News, 23 Jan. 2026

Outside encouragement can take root and become a personal goal, especially as Mars shifts into your foundational 4th house. —Tarot.com, Sun Sentinel, 23 Jan. 2026

But as anyone knows who’s ever lost — or even voluntarily relinquished — a foundational piece of themselves, to understand loss is not the same as to accept it. —David Ehrlich, IndieWire, 23 Jan. 2026

Word History

First Known Use

1657, in the meaning defined above

Rhymes for foundational

• formational
• gestational
• gradational
• locational
• mutational
• nonrational
• notational
• relational
• rotational
• sensational
• translational
• vibrational