verb
lurk
LURK/lɜːrk/
to remain hidden or unnoticed
She lurks behind a corner, unseen by the approaching man.

Etymology
Middle English lurken already meant to lie hidden and also came to describe moving secretly or escaping observation. The modern sense retains concealment as its core; the word's earlier Scandinavian origin is only probable.
In context
while behind mansion gates filth and corruption often lurk.
More examples
- He suspects a problem is lurking in the unfinished code.
- The stranger lurked near the gate without approaching.
- She prefers to lurk in the online discussion rather than post.
Forms
lurk · lurks · lurked · lurking