Absolutely! It was not really until the 20th century that the term came to be synonymous with the emotional, spiritual, and literal growth of young people.
The word originated in Germany during the late 18th century and came into prominence in the early 19th. The German root, "bildung" has several meanings, and is hard to translate. It can mean "novel of development" but its origins, in the Middle Ages, ("bildunge") meant man's communion with God.
According to Petra Rau, "The heydey of "bildungsroman" is undoubtedly the nineteenth century as a period of class conflict, social and social change throughout Europe and Britain which challenge and change the relationship between the individual and society."
Any individual in a novel, therefore, who experiences steady growth can be properly considered a "bildungsroman."