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.

---

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

---

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”; 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

Investors, still questioning whether a truce between the U.S. and Iran will last after their two-week cease-fire agreement, will be looking for company earnings to provide a solid fundamental underpinning for a jittery stock market.

From MarketWatch • Apr. 12, 2026

"Our data show that human connections and population interactions have been fundamental in driving cultural and technological innovations throughout history," he explains.

From Science Daily • Apr. 12, 2026

The column suggests that advanced AI systems have demonstrated a pattern of circumventing intended restrictions and safety constraints, raising fundamental questions about whether alignment with human values is achievable under current development approaches.

From Los Angeles Times • Apr. 10, 2026

He has also been questioning more fundamental assumptions.

From The Wall Street Journal • Apr. 9, 2026

Isolated victories can be won—even a string of victories—but in the absence of a fundamental shift in public consciousness, the system as a whole will remain intact.

From "The New Jim Crow" by Michelle Alexander

Related Words

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