Pronunciation: (fun"du-men'tl),[key] —adj. 1. serving as, or being an essential part of, a foundation or basis; basic; underlying: fundamental principles; the fundamental structure. 2. of, pertaining 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.
—n. 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 fun'damen'tal note', fun'damen'tal tone'.Music. a. the root of a chord.
b. the generator of a series of harmonics.
3. Physics.the component of lowest frequency in a composite wave.