The underlying features of an object, event, or situation are not obvious, and it may be difficult to discover or reveal them.
To stop a problem you have to understand its underlying causes.
要杜绝一个问题,你就必须认识其根本成因。
I think that the underlying problems are education, unemployment, and bad housing.
我认为潜在的问题是教育、失业和恶劣的居住条件。
You describe something as underlying when it is below the surface of something else.
hills with the hard underlying rock poking through the turf.
从草皮下凸出来的坚硬岩石堆成的山峦。