Lieutenant, a commissioned officer. In the United States Army, Air Force, and Marine Corps, lieutenants are the lowest-ranking commissioned officers. There are two grades, second lieutenant (the lower) and first lieutenant. In the Navy and Coast Guard, lieutenants rank above ensigns and below lieutenant commanders. Lieutenant junior grade is equivalent to an Army first lieutenant, and lieutenant is equivalent to an Army captain Originally the term lieutenant referred to any official, civil or military, who took the place of a superior.
Over the years, the science-fiction genre has amassed an impressive arsenal. Is anything from those fictional armories remotely close to becoming a reality?
Air Force, the air arm of a nation's military forces, usually separately organized as coequal with the army and the navy.