lurker

noun

lurk·er | \ ˈlər-kər

plural lurkers

Definition of lurker

1 : one that lies hidden in or as if in ambush a lurker in the shadows It troubled me that there should have been a lurker on the stairs, on that night of all nights in the year …— Charles Dickens

2 : a person who reads messages on an Internet discussion forum or social media platform but does not contribute Online fandom was a world where people were having conversations about the things they loved. For more than a decade, I was listening to the conversations, but I didn't say a word. I was a lurker.— Elizabeth Minkel