<p><strong>adjective</strong></p><ul><li>serving as, or being an essential part of, a foundation or basis; basic; underlying</li><li>of, relating to, or affecting the foundation or basis</li><li>being an original or primary source</li></ul><p><strong>noun</strong></p><ul><li>a basic principle, rule, law, or the like, that serves as the groundwork of a system; essential part</li><li>to master the fundamentals of a trade</li><li>also called fundamental note, the root of a chord</li><li>the generator of a series of harmonics</li><li>the component of lowest frequency in a composite wave</li></ul>