Ad nauseam is a Latin term used to describe an argument that has been continuing "[to the point of] nausea. For example, the phrase, "This topic has been discussed ad nauseam"; signifies that it has been discussed extensively, and that everyone involved is tired of that discussion. (The phrase is widely misspelled [/wiki/Special:Search?ns0=1&ns14=1&ns100=1&search=%22ad%20nauseum%22&fulltext=Search "ad nauseum"].)
This term is defined by the American Heritage Dictionary as:
"Argumentum ad nauseam or argument from repetition or argumentum ad infinitum is an argument made repeatedly (possibly by different people) until nobody cares to discuss it anymore. This may sometimes, but not always, be a form of proof by assertion."