adjective

forming a necessary base or core; of central importance. "the protection of fundamental human rights" синонимы: basic, foundational, rudimentary, elemental, elementary, underlying, basal, radical, root, primary, cardinal, initial, original, prime, first, primitive, primordial, principal, chief, capital, key, central, structural, organic, constitutional, inherent, intrinsic, ingrained, vital, essential, important, indispensable, necessary, crucial, pivotal, critical

noun

1. a central or primary rule or principle on which something is based. "two courses cover the fundamentals of microbiology" синонимы: basics, essentials, rudiments, foundations, basic principles, first principles, preliminaries, crux, essence, core, nucleus, heart, base, bedrock, groundwork, crux of the matter, heart of the matter, sine qua non, nuts and bolts, nitty-gritty, brass tacks, ABC
2. a fundamental note, tone, or frequency.