The most basic possible interpretation of "feminism" is that women should have the same rights in the the face of law and the government as men.

I personally believe that someone (male or female) who does not agree with that stance is TA.

Even if you are a woman and you do not believe that women should have the same rights as men in a legal sense, then you are still TA. You may not care about those right, but you don't get to deprive others of your gender of those rights.

If you have a different definition of feminism, then you need to do a better job at articulating what exactly that is and why you disagree with it. It seems to be fashionable these days for young conservative women to say that they are not feminists.