Dreadful woe - I'll hide away (3,3)
I believe the answer is:
lie low
'hide away' is the definition.
'dreadful woe i'll' is the wordplay.
'dreadful' indicates anagramming the letters.
'woe'+'ill'='woeill'
'woeill' with letters rearranged gives 'LIE LOW'.
(Other definitions for lie low that I've seen before include "Conceal oneself, don't be conspicuous" , "'Keep out of sight, avoid attention (3,3)'" , "Be inconspicuous - in horizontal position?" , "Conceal oneself in recumbent posture?" , "Stay doggo" .)