From unnecessary scarf wearer. This is a person of western background, usually Caucasian, found in Cairo, Egypt. Not all westerners in Cairo are scarf-wearers: scarf-wearers are people who work for NGOs or similar, and are studying Arabic. The term stems from their ubiquitous habit of draping at least one scarf bought from Khan el Khalili, the old market, around themselves in an effort to appear "ethnic" and in their fervour to kowtow to what they believe are Egyptian norms. In reality, they end up dressed more modestly than the weather or the culture necessitates. Female scarf-wearers will also love long flowing skirts and dresses with no particular shape, birkenstocks or leather Jesus sandals, stringy jewellery, and will wear no makeup. Their hair will also be uncared for. Inevitably they will have a massive bag with them made of hemp or bedouin cloth. Male scarf-wearers will have ill-fitting trousers also made of hemp, scraggly t-shirts or "ethnic" shirts bought from Khan el Khalili, and the most radical practitioners may have a Palestinian kuffiya draped around their necks. They will have longish unkempt hair and beards. All of these people will have an Arabic textbook on their person.
Scarf-wearers will divide their time between "real" parts of Cairo, looking around and doing good works and buying ironic things, Dahab, where they will smoke up on cushions by the Red Sea, and going to nice bars and parties in Cairo with Egyptian guys who want to have sex with them. Whenever possible they will eat Egyptian street food, really courting disaster. After around a year spent in Egypt, they usually return to wearing the appropriate amount of scarves and real trousers and doing something with their hair.
Girl: Have you met your new American co-worker yet?
NGO chick: Yeah, she eats foul and taamiya every day. I haven't seen her arms yet even though it is August. She's a hardcore scarf-wearer.