Here's a breakdown:
* Heckling: The act of interrupting a speaker with unfriendly or disapproving comments.
* Heckler: The person who heckles.
Example:
"The comedian was heckled by a drunk man in the front row, who kept shouting insults."
Heckling is a form of disruptive behavior that can be annoying, disrespectful, and sometimes even dangerous.