Bunbury is defined as an imaginary person whose name is used as an excuse to some purpose, especially to visit a place. It means "to use the name of a fictitious person as an excuse" which is derived from Oscar Wilde's play "The Importance of Being Earnest" where the character Algernon invents an imaginary person named Bunbury as an alibi to escape from relatives. He explains to his friend, "I have invented an invaluable permanent invalid called Bunbury, in order that I may be able to go down into the country whenever I choose. Bunbury is perfectly invaluable.