The act of removing any and all usefulness from something in such a manner that what remains is also worthless. Human males, in particular.
It was a terrible experience to watch her degonadularize him as they broke up. Now, all he does it sit around and watch Lifetime(tm) television all day.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi