fun·da·men·tal / ˌfəndəˈmentl/ • adj. forming a necessary base or core; of central importance: the protection of fundamental human rights interpretation of evidence is fundamental to the historian's craft. ∎  affecting or relating to the essential nature of something or the crucial point about an issue: the fundamental problem remains that of the housing shortage. ∎  so basic as to be hard to alter, resolve, or overcome: the theories are based on a fundamental error.• n. (usu. fundamentals) a central or primary rule or principle on which something is based: two courses cover the fundamentals of microbiology. ∎  a fundamental note, tone, or frequency.DERIVATIVES: fun·da·men·tal·i·ty / ˌfəndəmənˈtalətē/ n.

fundamental. A chord in which the lowest note is that from which the chord is derived. Fundamental bass is the imaginary bass of a passage, consisting not of its actual bass notes but of the roots of its chords, i.e. the bass of its chords when in root position.