na-adjective
Describes something that forms the foundation or essential basis of a field, skill, or concept. Often used in academic or technical contexts.
数学の基礎的な知識が必要です。
Basic knowledge of mathematics is necessary.
この本は経済学の基礎的な概念を説明している。
This book explains the fundamental concepts of economics.
From 基礎 (foundation, basis) + 的 (-like, -ic).