abstruse

It is often used to describe a concept, theory, or piece of information that is not easily grasped by the average person. This word is often used to describe something that is profound, recondite or esoteric, requiring a high degree of knowledge or expertise to fully comprehend. It can also be used to describe a text, a book, an article or a lecture that is hard to understand or follow. Abstruse can also be used to describe a person who is known for their complexity or difficulty to be understood in their thinking and communication. In a negative sense, it can be used to describe something that is too complex or hard to understand, but in a positive sense, it can be used to describe something that is intellectually stimulating or challenging.