Usually it is a surname according to dictionary. But I have seen people called Lambert by given name. Maybe things have been changing.
Lambert1.[男子名] [英格兰人姓氏] 兰伯特.来源于日耳曼语人名,含义是“土地,领土+光明的,著名的”(lan
Usually it is a surname according to dictionary. But I have seen people called Lambert by given name. Maybe things have been changing.