In money talk, gilt-edged stocks or shares are the very safe kind, sold mainly by governments. They do not pay you much extra money — the interest is low — but people buy them because they are unlikely to fail. British people often just say gilts for their government’s own bonds. The picture behind the word is gold on the edge: fine books and old certificates had a thin gold edge, a sign of quality, and government paper used to be marked that way. So gilt-edged came to mean “as safe and respectable as you can get.” People still also use it in the older, literal way for a book or card with gold along the edges, and sometimes, a little loosely, for anything they want to call first-class. In a business or exam question about stocks, though, it means the safe government kind, not jewellery.