A beard worn by a resident of the stylish neighborhood, Williamsburg, Brooklyn. Beards are very fashionable in Williamsburg, so a hipster with a beard is Williamsbeard. It can be used as an adjective, too, to describe an event or thing that is popular with happening, bearded people.
"You know Eric, he's one of my friends from Bard - he lives off Lorimer St. and has a Williamsbeard."
"I was trying to get into that Band of Horses CD but it was just too Williamsbeard for me."
"I left that loft party because it was just too Williamsbeard, plus they were out of beer, and everyone was looking at me funny for not wearing cut-off jeans."