lurk
[verb]
Synonyms: hide, conceal oneself, lie in wait, prowl, skulk, slink, sneak

[TahlilGaran] English Synonym Dictionary ▲

lurk /lɜːk $ lɜːrk/ verb [intransitive]
[Date: 1200-1300; Origin: Probably from Low German or a Scandinavian language]

1. to wait somewhere quietly and secretly, usually because you are going to do something wrong
lurk in/behind/beneath/around etc
She didn’t see the figure lurking behind the bushes.

2. if something such as danger, a feeling etc lurks somewhere, it exists, but you may not see it or know about it:
a dark formless danger, lurking in the shadows

3. if you lurk in a chat room on the Internet, you read what other people are writing to each other, but you do not write any messages yourself
lurk in
I think it’s sort of creepy how people lurk in chat rooms.

[TahlilGaran] Dictionary of Contemporary English ▲