One of the most hilarious moments in my life was watching my mother-in-law casually use the word "fanny" in front of our entire Irish extended family, and seeing their reactions. I believe the verbatim was "carting their fannies around". (As in, she was driving folks to various destinations in a rental car.) She may have also used the phrase "giving rides" in conjunction.

Even little kids say this in America, it's the equivalent of "bum" really, and isn't associated with a specific gender. The reactions on the faces of these people, some of whom we were meeting for the first time, were truly priceless.