The word feminism is not well defined. As it is commonly used it would be roughly defined as: a movement for the empowerment of woment. Some people seem to try to define it in terms of equality, but in its most common usage that definition is definitely off the mark.
I think its funny that a word that is used so often is so poorly defined. Similarly, the word "racism" is also not very well defined, even though it is used so often. Per it's common usage seems to roughly translate to: "discrimination against a racial group which is a minority within the United States." No dictionary would define it this way, but that is precisely how the word is commonly used.
Not really what your post was actually about, but I think it brings attention to the fact that there are many words in heavy use that are not well-defined which results in alot of confusion (some of it on purpose).