ON a recent night at Hotel Delmano, a stylish speakeasy in Williamsburg, Brooklyn, the heavily tattooed head bartender, Sam Anderson, and his colleague, Michaelangelo Davis III, were shaking up cocktails with manly vigor.

And each had his hair done up in a bun.

In certain arty neighborhoods like Williamsburg and Bushwick, some men are twisting their long hair into a form more famously worn by librarians, schoolmarms and Katharine Hepburn. But don’t call the male version an up-do or a chignon. Call it a man bun.

The line between utilitarian convenience and fashion statement can be hard to draw with the man bun. On the tennis court, players like Alexandr Dolgopolov and Xavier Malisse have been known to wear them. Certainly, there and in the food and beverage industry, keeping hair away from the face is important. And at Hotel Delmano, Mr. Davis, 26, sometimes uses his abundant bun as a pen holder.

But he and Mr. Anderson could not hold up their heads wearing hairnets. As for ponytails, to Mr. Anderson, 30, they evoke “Steven Seagal, hippie uncles and the like,” and would not be a good fit in this neighborhood. A hat is an option, but a bun is less sweaty.