forming a necessary base or core; of central importance:

基本的な, 根本的な

e.g. the protection of fundamental human rights

«…にとって» 必須の «to»

e.g. 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:

根底をなす, 重要な

e.g. the fundamental problem remains that of the housing shortage.

so basic as to be hard to alter, resolve, or overcome:

e.g. the theories are based on a fundamental error.

noun (usually fundamentals)

a central or primary rule or principle on which something is based:

〖通例～s〗 基本, 根本; 原理, 原則

e.g. two courses cover the fundamentals of microbiology.

a fundamental note, tone, or frequency.

〘楽〙 (和音の)根音, 基音

fundamentality |ˌfəndəmənˈtalətē| noun

late Middle English: from French fondamental, or late Latin fundamentalis, from Latin fundamentum, from fundare ‘to found’.