Argument from repetition
Argument from repetition, is an argument made repeatedly (possibly by different people) until nobody cares to discuss it any more. The fallacy is also called argumentum ad infinitum ('to infinity'), argumentum ad nauseam and it is an informal fallacy.
The sentence 'This topic has been discussed ad nauseam' signifies that the topic in question has been discussed extensively, and that those involved in the discussion have grown tired of it.
Comment fallacy in argument from repetition on Reddit to explain this fallacy. ?