skulk /skʌlk/ BrE AmE verb [intransitive always + adverb/preposition]
[ Date: 1100-1200 ; Origin: From a Scandinavian language ]
to hide or move about secretly, trying not to be noticed, especially when you are intending to do something bad SYN lurk
skulk about/around/in etc
He was still skulking around outside when they left the building.