A person or thing that causes annoyance; someone who is annoying.
From 'annoy' (from Old French 'anoier,' possibly from Latin 'in odio') plus the agent suffix '-ancer' (one who does something), though this form is archaic and rarely used.
This word shows how English once loved adding '-ancer' to make job titles (like 'dancer'), but we've mostly dropped it for '-er'—'annoyancer' sounds old-fashioned now, which is kind of fitting for something meant to bother people.
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