The word "boo" is not just a sound used to frighten or disapprove; it has found its way into various forms of media, including literature, movies, and music, often used to evoke a sense of tension or humor. It has been used in popular films to denote a ghostly or eerie presence, and also as a playful form of interaction in sports events, where fans "boo" their opponents to show disapproval.
While "boo" remains an informal expression, its impact on language and culture is significant, especially in terms of how it conveys emotion and social reaction. The evolution of this simple exclamation reflects the fluid nature of language and its ability to adapt to different cultural contexts.