Okay this makes sense. I don't have an overwhelming opinion either way so I wouldn't be a feminist but this is a much better explanation than what I usually hear. Is there any "official" definition?
Not a definition that is commonly agreed upon, no. This thread has outlined some of the basic splits: essentialist (there are attitudes that are uniquely/essentially womanly) vs. social constructivist (everything about being womanly is taught/enforced by society), feminism as a radical stance of activism vs. the quiet belief that women are people, and the exact definition of equality.
Most definitions boil down to the bumper sticker slogan professing that "feminism is the radical notion that women are people." Compressing the definitions that far destroys a lot of the nuance, however.
On my right, I have one definition by feminist theorist bell hooks (who one can quickly tell is pretty radical, on account of her challenging of capital letters): "Simply put, feminism is a movement to end sexism, sexist exploitation, and oppression... Practically, it is a definition which implies that all sexist thinking and action is the problem, whether those who perpetuate it are female or male, child or adult. It is also broad enough to include an understanding of systemic institutionalized sexism.
From its earliest inception feminist movement was polarized. Reformist thinkers chose to emphasize gender equality. Revolutionary thinkers did not want simply to alter the existing system so that women would have more rights. We wanted to transform that system, to bring an end to patriarchy and sexism... The vision of "women's liberation" which captured and still holds the public imagination was the one representing women as wanting what men had. And this was the vision that was easier to realize. Changes in our nation's economy, economic depression, the loss of jobs, etc. made the climate ripe for our nation's citizens to accept the notion of gender equality in the workforce.
Five responses while I'm typing this? Daaang.