'commenter' originates from English, specifically from the verb 'comment' with the agentive suffix '-er' meaning 'one who comments'.

'comment' entered English from Old French (e.g. 'comenter') and ultimately from Latin 'commentari' / 'commentum' (meaning a consideration, contrivance); English 'comment' developed from these forms, and the agentive suffix '-er' was later added to form 'commenter'.

Initially related to Latin ideas of 'considering' or a 'note/contrivance'; over time it came to mean 'to make a remark', and 'commenter' specifically became 'one who makes a remark' (now often used for people posting opinions online or in media).