Try to be inconspicuous (3,3)
I believe the answer is:
lie low
'try to be inconspicuous' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lie low that I've seen before include "Absent oneself from social contact (for a period)" , "Stay out of sight, be inconspicuous" , "Conceal oneself or one's intentions" , "Keep hidden" , "Conceal oneself, don't be conspicuous" .)