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

Marc Alessi, a science fellow at the Union of Concerned Scientists, told AFP the heat wave is "occurring in a fundamentally different system" under the influence of human-caused climate change.

From Barron's • Jul. 10, 2026

He believes long-term customer agreements will fundamentally improve revenue visibility and predictability for these companies.

From MarketWatch • Jul. 8, 2026

The enclosed venue is fundamentally a product of the television economy.

From The Wall Street Journal • Jul. 8, 2026

"Anything that was a reference to reality was to be removed," he said, arguing that the changes would have fundamentally alter the film.

From BBC • Jul. 6, 2026

That life has changed fundamentally over the aeons is entirely clear from the alterations we have made in the beasts and vegetables during the short tenure of humans on Earth, and from the fossil evidence.

From "Cosmos" by Carl Sagan