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

See Examples For:

fundamental

Aluminum is rightly treated as a national-security industry, since it’s a fundamental input for military systems and hardware.

From MarketWatch ● Aug. 31, 2026

Although the work deals with some of the most fundamental questions in physics, research into basic laws of nature has historically produced major practical benefits.

From Science Daily ● Aug. 30, 2026

"The stability of Niger is fundamental to the security of the entire Sahel region, crucial also for countering illicit trafficking and irregular migratory flows," Tajani said.

From Barron's ● Aug. 30, 2026

Donald’s natural ability, his attention to detail and fundamental technique remain “off the charts,” Smith said.

From Los Angeles Times ● Aug. 30, 2026

This discovery presented fundamental difficulties for any account of how the compass worked, but it also raised the exciting possibility that variation might be sufficiently regular for it to be used to measure longitude.

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