ground noun (AREA OF KNOWLEDGE)
C2 [U] an area of knowledge or experience: When the conversation turns to politics he's on familiar ground (= he knows a lot about this subject). Once we'd found some common ground (= things we both knew about) we got on very well together. The lectures covered a lot of ground (= included information on many different subjects). I enjoyed her first novel, but I felt in the second she was going over the same ground (= dealing with the same area of experience).
Student or Learner