fundamental

American  

[fuhn-duh-men-tl] / ˌfʌn dəˈmɛn tl /

adjective

1. serving as, or being an essential part of, a foundation or basis; basic; underlying.

   fundamental principles;

   the fundamental structure.

   Synonyms:

   primary, indispensable

2. of, relating to, or affecting the foundation or basis.

   a fundamental revision.

3. being an original or primary source.

   a fundamental idea.

4. Music. (of a chord) having its root as its lowest note.

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noun

1. a basic principle, rule, law, or the like, that serves as the groundwork of a system; essential part.

   to master the fundamentals of a trade.

2. Also called fundamental tone.  Also called fundamental note,.  Music.

   1. the root of a chord.

   2. the generator of a series of harmonics.

3. Physics. the component of lowest frequency in a composite wave.

fundamental British  

/ ˌfʌndəˈmɛntəl /

adjective

1. of, involving, or comprising a foundation; basic

2. of, involving, or comprising a source; primary

3. music denoting or relating to the principal or lowest note of a harmonic series

4. of or concerned with the component of lowest frequency in a complex vibration

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noun

1. a principle, law, etc, that serves as the basis of an idea or system

2. 1. the principal or lowest note of a harmonic series

   2. the bass note of a chord in root position

3. Also called: fundamental frequency.   first harmonic.  physics

   1. the component of lowest frequency in a complex vibration

   2. the frequency of this component

Other Word Forms

• fundamentality noun
• fundamentally adverb
• fundamentalness noun
• nonfundamental adjective
• nonfundamentally adverb
• unfundamental adjective
• unfundamentally adverb

Etymology

Origin of fundamental

First recorded in 1400–50; late Middle English, from Medieval Latin fundāmentālis “of, belonging to a foundation”; see fundament, -al ¹

Explanation

When asked what the fundamental, or essential, principles of life are, a teenager might reply, "Breathe. Be a good friend. Eat chocolate. Get gas money." Fundamental has its roots in the Latin word fundamentum, which means "foundation." So if something is fundamental, it is a key point or underlying issue — the foundation, if you will — that the thing is built upon. Teachers argue that math fundamentals include memorizing the times tables and understanding long division. Many people would also argue that math fundamentals should include knowing how to use a calculator and knowing where the calculator's extra batteries are kept.

Example Sentences

Whether you are a veteran investor, a novice or a trader, it is useful to be reminded of fundamental principles that can help you to stay disciplined as you build wealth.

From MarketWatch • Apr. 17, 2026

As Barron’s reported on Wednesday, the fundamental problems that have dragged down the sector remain.

From Barron's • Apr. 16, 2026

Dr Lawrence Hill-Cawthorne, co-director of the Centre for International Law at the University of Bristol, reiterated that the "fundamental rule of law" is that civilian objects must not be targeted.

From BBC • Apr. 16, 2026

The willingness to make the big cuts reflect a fundamental shift in how U.S. companies view their professional talent.

From The Wall Street Journal • Apr. 16, 2026

This story is a fine example of two fundamental features of the Scientific Revolution.

From "The Invention of Science" by David Wootton

Related Words

• central
• constitutional
• crucial
• elemental
• elementary
• essential
• indispensable
• integral
• intrinsic
• major
• necessary
• paramount
• principal
• radical
• significant
• structural
• theoretical
• underlying
• vital