Go to ground? (3,3)
I believe the answer is:
lie low
'go to ground' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for lie low that I've seen before include "don't show your face" , "Keep one's head down" , "Absent oneself from social contact (for a period)" , "Use bottom bunk, perhaps" , "Keep hidden" .)