Lie low (5)
(Other definitions for skulk that I've seen before include "Lie in wait" , "Lurk or loiter stealthily" , "Move secretly" .)
'lie low' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for hide that I've seen before include "harbour" , "Secrete, conceal" , "Flog" , "Conceal with leather" , "A flower; an instrument" .)