abstruse
US /æbˈstruːs/
UK /æbˈstruːs/

1.
深奥的, 难懂的, 晦涩的
difficult to understand; obscure
:
•
The philosopher's writings were too abstruse for the average reader.
这位哲学家的著作对于普通读者来说过于深奥。
•
He often uses abstruse terminology that only experts can grasp.
他经常使用只有专家才能理解的深奥术语。