My favorite pet name for it is a jewfro
Not to stereotype or offend, but when people say somebody "looks Jewish" they typically have curly black hair, at least in the hair department, frequently thinning if you're an older male. Length usually isn't an issue, provided it's curly, like Bob Dylan, or Art Garfunkel (he's blonde).
My hair is dark, thick, and curly, and since I look the part in a few other ways (but not unibrow), people frequently assume I'm Jewish. Apparently I screw up people's Jewdar.
You don't have to be Jewish to have the hair. The hair is typical of all Eastern Europeans, and part of the American Jewish population, very few in Israel. Interesting.
A lot of people at NYU have the hairstyle, and they're not all Jewish, but a disproportionately high number are.