na-adjective, noun
difficult to understand; abstruse; unintelligible
Describes texts, concepts, or explanations that are hard to comprehend due to complexity or obscurity. Often used for academic, technical, or philosophical content.
この論文は難解で、何度読んでも理解できない。
This paper is abstruse; no matter how many times I read it, I can't understand it.
彼の説明は難解すぎて、誰もついていけなかった。
His explanation was too difficult to follow, and no one could keep up.