Well, even though the Oxford can say one thing, the reality is that feminism means different things to different people. This is called a: "Discoursal Schism" if anyone cares.
It can range in meaning drastically. Let's take an example: If I say the word "dog," you might think about Lassie saving Timmy from a well, and I might think about my retriever urinating on my couch. And still another person might have been mauled by a dog as a child, and have a flashback. Words have different meanings depending on the individual.
I did not identify myself as a "feminist" until I entered college, and I met some very intelligent and even-handed feminists, like our professor who taught feminist literature. Really, the problem with feminism tends to be -like anything else- people jumping onto the bandwagon without thinking, and becoming zealous foot-soldiers in the movement just because their ex-boyfriend was a pig, or something like that. But, the people who study the actual history and philosophy of feminism I have tremendous respect for.