fundamentally

American  

[fuhn-duh-men-tl-ee] / ˌfʌn dəˈmɛn tl i /

adverb

1. in a fundamental and essential way; centrally and foundationally.

   a nine-point plan that will fundamentally transform our system of eldercare.

2. as regards the basic nature, character, or truth of something; basically and often emphatically.

   Fundamentally, they just want their independence.

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fundamentally British  

/ ˌfʌndəˈmɛntəlɪ /

adverb

1. in a way that affects the basis or essentials; utterly

   the terms of engagement have been fundamentally altered

2. (sentence modifier) in essence; at heart

   fundamentally, we want our lives to be safe

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Other Word Forms

• nonfundamentally adverb
• unfundamentally adverb

Etymology

Origin of fundamentally

First recorded in 1600–20; fundamental ( def. ) + -ly ( def. )

Explanation

The word fundamentally isn’t fun, exactly, but it does describe things that are true through and through. Vegetarians and meat eaters often have fundamentally different ideas about what makes a healthy meal. Anything fundamental has to do with the foundation or bare bones of something. Similarly, anything described fundamentally is getting down to the essence. Lying is fundamentally dishonest. If something is fundamentally wrong, don’t do it! If you and your dad have fundamentally different opinions about restaurants, it’s better to make dinner at home. This word means about the same as basically or essentially. If something is fundamentally true, it's true in a deep sense.

Example Sentences

Cryptocurrencies are fundamentally unsuitable for retirement accounts due to extreme volatility and the fact that they lack concrete underlying value.

From Los Angeles Times • Apr. 10, 2026

He wanted to convince the justices that this was not merely a preservation dispute but a case in which the trial court had fundamentally failed to carry out Batson’s third step.

From Slate • Apr. 10, 2026

The transition from ancient cultivation to large scale industrial farming has fundamentally altered the structure and strategy of one of the world's most important food crops.

From Science Daily • Apr. 8, 2026

"AI capabilities have crossed a threshold that fundamentally changes the urgency required to protect critical infrastructure from cyber threats, and there is no going back."

From Barron's • Apr. 7, 2026

The picture is fundamentally like a newspaper wirephoto, made of perhaps a million individual dots, each a different shade of gray, so fine and close together that at a distance the constituent dots are invisible.

From "Cosmos" by Carl Sagan