Abstract concept is a concept which is not directly connected to system's receptors.
Abstract concept is connected with other concepts though. Abstract concept is connected to receptors indirectly through non-abstract concepts (surface concepts).
It's not easy task to identify and create an abstract concept. You cannot just borrow it from external world as surface concepts.
What do you think: is it good idea to name such abstact concept as Deep Concept?
It may help to distinguish abstract concepts which are available in books from abstract concepts which must be created by AI itself.