'lurker' originates from Middle English, specifically the word 'lurken', where the form likely imitated stealthy movement.

'lurker' changed from Middle English 'lurken' (a verbal form related to 'lurk') and evolved into the modern English noun 'lurker' by adding the agentive suffix '-er'.

Initially, it meant 'to lie hidden or move stealthily'; over time the core sense remained but extended into figurative uses, including the modern internet sense of someone who reads without posting.