The term "Beatrice Lillie" refers to a specific person rather than a general English word. Here’s an easy explanation for new English learners:
Beatrice Lillie was a famous British actress born in Canada in 1898. She is known for her work in theatre, film, and television, and she was especially popular in the early to mid-20th century. Beatrice Lillie was celebrated for her comedic talent and her unique style of performance. She passed away in 1989.