Take your regular
feminist: take away the idea of equality, take away all trace of rationality, add hate for everything fun/male, boost it with the unlimited ignorance of the special snowflake community of
TumblrTadaaa! You've got a feminazist!
Now take your feminazist and add about 5,000 more of them. Now they all share the same ignorant ideology and then we can add "ism" to
feminaziTaadaaaa! Now we got feminazism