Definitely a hot-button topic lately. I know people have a hard time wrapping their minds around these definitions for different reasons. Usually, it has to do with some sort of investment in them being applied a certain way. I would have to agree with K.M. Noble in that this question is often loaded and can be used to exclude. The only time I run into a real practical application for definitions is when I'm at the doctor's office and they ask when my last menstrual cycle was. Then there's a need for some definition!