Definition from Nolo’s Plain-English Law Dictionary
A military officer who is part of the Judge Advocate General's Corps. The Corps is the judicial arm of each of the U.S. armed forces. Judge advocates are charged with upholding military law, as contained in the Uniform Code of Military Justice. Officers of the Corps are the chief officers in courts-martial and military courts of inquiry. Judge advocates also provide legal services to servicemembers, and advise commanders on the laws concerning armed combat.