heckler
A person who rudely interrupts a speaker to bother or upset them.
A heckler is someone who interrupts a public speaker or performer with rude comments, questions, or jokes meant to disrupt or embarrass them.
You might encounter hecklers at comedy shows, where someone in the audience yells out during a comedian's act. Politicians giving speeches sometimes face hecklers who shout disagreements or accusations. Even at a school assembly, a student who keeps making disruptive comments while the principal is talking could be called a heckler.
The key element of heckling is that it's meant to throw someone off or undermine them, not to have a genuine conversation. A heckler isn't asking an honest question or offering constructive feedback. They're trying to rattle the speaker, make them look foolish, or draw attention to themselves.
Most skilled performers know how to handle hecklers with quick, clever responses that win back the audience. Some comedians are famous for their sharp comebacks to hecklers. But dealing with heckling requires focus and confidence, since the heckler's goal is to make the speaker lose their composure.
The verb form is heckle: “The crowd began to heckle the speaker.”