lurks; lurked; lurking
1 : to be in a hidden place
The cat was lurking [=hiding] behind the sofa.
: to wait in a secret or hidden place especially in order to do something wrong or harmful
She could tell there was someone out there lurking in the shadows.
— often used figuratively
Trouble lurks around every corner.
There is tenderness that lurks underneath his tough appearance.
Who knows what evil lurks in the hearts of men?
The idea had been lurking in her mind for some time.
2 computers : to read messages written by other people on the Internet in a newsgroup, chat room, etc., without writing any messages yourself
— lurker noun, plural lurkers [count]