High ground dropped away (4)
I believe the answer is:
fell
This could be a double definition.
'high ground' is the first definition.
'fell' can be an answer for 'ground' (thesaurus). I'm not certain of the 'high' bit.
'dropped away' is the second definition.
'fell' can be an answer for 'dropped' (I've seen this in another clue). I am unsure of the 'away' bit.
Can you help me to learn more?
(Other definitions for fell that I've seen before include "Destructive; a hill" , "Knock down - or was knocked down?" , "Abated" , "Keeled over" , "northern mountain" .)