It makes you Arab American or African American or whatever you choose to classify yourself as. The question asks what you identify yourself as. If you think you're African American, check it. If you think you're Caucasian, check it. It's only likely to become an issue for you if you identified as a Caucasian on official forms all your life, and now magically realize you're African American. That might come up during C&F for the bar. From the fact that you're only now asking whether you can identify as a minority, I'm guessing that you never have before and thus you'll probably get a nice committee meeting at the bar when they discover the inconsistency. Not sure why this was posted in this forum rather than the general forums. Nobody here has special insight on this aspect of admissions.
Thanks for the response. The reason I posted on this forum is because it's one of the more active URM sections and I would imagine that a lot of people who follow this section of LSD actually DO have a little more insight regarding this aspect of admissions. There are plenty of people who do not fit neatly into these racial categories, and while I'm not necessarily looking for someone with my exact family background, I'd expect to find a few people who have been thoroughly confused about what to mark down (and I'm not just talking about identity issues stemming from having a minority grandparent, for example). I did not realize that African American exclusively referred to Black people of sub-Saharan African descent, and that there was an official differentiation made between North Africans and sub-Saharan Africans.
Also, I did not "magically realize I was African American"...and I've always self-identified as a minority (and I've always selected "other" on all official applications etc). The "white" definition you posted was definitely an interesting one...it's good to know that this is officially how the gov't sees racial divisions in the world, but I think you'd find very few Arabs who would go along with that categorization, right or wrong. If the issue is purely one of skin color/appearance, then I most certainly do not understand how Middle East/N Africa is categorized along with Germany and Ireland, etc.
Anyway, if this question was irrelevant or inappropriate somehow, my apologies. There's few places outside of LSD and TLS where I can ask these questions, and I appreciate both you guys getting back to me. I won't claim URM status as either African or Asian, but I'll definitely continue selecting "other".