The meaning of FUNDAMENTAL is serving as a basis supporting existence or determining essential structure or function : basic.

FUNDAMENTAL definition: serving as, or being an essential part of, a foundation or basis; basic; underlying. See examples of fundamental used in a sentence.

FUNDAMENTAL definition: 1. forming the base, from which everything else develops: 2. more important than anything else…. Learn more.

You use fundamental to describe things, activities, and principles that are very important or essential. They affect the basic nature of other things or are the most important element upon which other …

basic: fundamental principles of physics. essential: a fundamental revision of a theory. being a starting point: a fundamental idea. a basic principle, rule, law, or the like: the fundamentals of engineering. …

Jan 14, 2026 · fundamental (plural fundamentals) (generic, singular) A basic truth, elementary concept, principle, rule, or law. An individual fundamental will often serve as a building block used to form a …

1. serving as, or being an essential part of, a foundation or basis; basic; underlying: fundamental principles. 2. of, pertaining to, or affecting the foundation or basis: a fundamental revision. 3. being …

There are 17 meanings listed in OED's entry for the word fundamental, three of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

Fundamental refers to something that is essential, basic, or foundational. It can denote core principles, key elements, or the underlying basis on which something is built or understood.

Definition of fundamental. English dictionary and integrated thesaurus for learners, writers, teachers, and students with advanced, intermediate, and beginner levels.