What is another word for boo?
Pronunciation: [bˈuː] (IPA) 
The word "boo" is commonly used to convey disapproval or to scare someone. Some synonyms for "boo" include hiss, jeer, taunt, and heckle. A hiss is a sharp sound made by forcing air through a small opening in the mouth, and can be used to express disapproval. Jeering involves mocking someone, often by shouting insults or making fun of them. Taunting is a similar action, but typically involves teasing or provoking someone. Heckling is also similar to jeering and taunting, but often involves interrupting a speaker or performer with critical comments. Each of these words can be used in place of "boo" to convey similar meanings.
