means A person who reads or observes an online community without ever posting or contributing, watching from the shadows.

from From "lurk," which entered English in the late Middle Ages, likely from a Scandinavian source related to dialect words for sneaking or sulking, and possibly tied to "lower" in the sense of looking dark or menacing. For centuries it meant to lie in wait, often with sinister intent — the lurker was a hider in alleys, a predator in ambush. The internet softened the menace but kept the stealth: the modern lurker waits in the digital underbrush, present but unseen, watching the conversation without ever stepping into the light.