When I say I'm vegan, I'm now defining it in the most serious of terms, to get it through people's heads it's not just some fad. So I define vegan as (which it is) a political, social justice movement. This definition, in my opinion, makes it sound a lot more powerful, and places it where it deserves, alongside other issues like, pro-life/pro-choice, human rights, GLBTQ rights, etc. which are also political, social justice movements. Then if I talk further with the person, I go into detail what veganism is all about.
People never say they are, for instance, pro-life, for human rights, etc., because of ethical reasons. Why should animal rights activists?
Saying words like "ethical", "philosophical", (or "plant-based", which is a term I have never used) just doesn't hold power like saying "political" and "social justice"; there seems to be more respect when those two words are stated. This is from my own personal experience when I speak to people.
So I tell people I'm vegan for political, social justice reasons.
