This charming slang possibly began as a pet name for “Louise,” but it evolved into a casual reference for an outstanding person in their field, or a stellar example of a specific category. The Nobel Prize, for example, is awarded to lulus from a variety of different backgrounds, including scientists, writers, and progenitors of peace. The Pulitzer Prize is awarded to pieces of writing considered lulus in categories such as General Fiction, and also to people who are lulus for their work in categories such as International Reporting.