When I use the words "femininity" and "masculinity," I use them to denote the characteristics that most English speakers mean by the words. Here are some examples:
There is some uneasiness about using the words this way. Another view is that the words should not mean anything because any attempt to categories gender qualities is, at best, giving in to the binary and, at worst, just plain sexist. In this view, the words have no meaning or have only inaccurate meaning. I don't like this view because it throws out two words and doesn't supply a replacement. Another view is to use the words to mean the characteristics that innate in the biology of females in males. The problem with this is there are very few qualities (if any!) that are innately different between the sexes. The characteristics would be too few and too risky to make the words worth anything, so again I lose the words. So I use the words to be consistent with my own semantics, that are the most useful because most people will understand them, and the only way consistent with my ideology. Other people, however, are free to do whatever they want.