lurk

(verb) lie in wait, lie in ambush, behave in a sneaky and secretive manner. Synonyms: skulk.

(verb) be about. Synonyms: loiter, lounge, footle, lollygag, loaf, lallygag, hang around, mess about, tarry, linger, mill about, mill around. Examples: "The high school students like to loiter in the central square." "Who is this man that is hanging around the department?."

(verb) wait in hiding to attack. Synonyms: ambush, scupper, bushwhack, waylay, ambuscade, lie in wait.