Hill of CNN (5)
I believe the answer is:
'hill of cnn' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for erica that I've seen before include "growing up on the moors" , "hardy shrub" , "Shrub genus; girl's name" , "Girl's name - heather" , "Heath genus; girl's name" .)