白 is white, 毫 is hair, 銀 is silver, and 針 is needle, so the full name is white hair silver needle. White hair describes the downy exterior of the buds, while silver needle refers to the shape of the buds. But usually it's just 銀針 (silver needle).
About This Dish
Silver needle tea, also listed by its Mandarin pronunciation baihao yinzhen, is the premium (as in expensive) white tea. It's harvested early, before the buds have opened.