"JD" can refer to a few different things, most commonly a Juris Doctor degree, which is a professional doctorate and the primary law degree in the United States. It signifies that the holder has completed law school and is qualified to sit for the bar exam to become a practicing lawyer. Alternatively, "JD" can stand for "John Deere," the well-known agricultural and construction equipment manufacturer. Without more context, it's difficult to know which meaning is intended.