silver bullet (n.)Related entries & more
"very effective, almost magical remedy," 1808. The belief in the magical power of silver weapons to conquer foes goes back at least to ancient Greece (as in Delphic Oracle's advice to Philip of Macedon).
Brother Jonathan (n.)Related entries & more
sobriquet for "United States," 1816, often connected with Jonathan Trumbull (1740-1809) of Connecticut, who was called Brother Jonathan by George Washington, who often sought his advice, somehow in reference to 2 Sam i:26.
brain trust (n.)Related entries & more
back seat (n.)Related entries & more
You know him. The one who sits on the back seat and tells the driver what to do. He issues a lot of instructions, gives advice, offers no end of criticism and doesn't do a bit of work. ["The Back Seat Driver," Wisconsin Congregational Church Life, May 1923]