What is the term for someone who is extremely angry?

The term for someone who is extremely angry is "irate." This word conveys a heightened level of anger, often implying a deep emotional response to a situation. "Irate" is derived from the Latin word "iratus," meaning angry or enraged, and it is commonly used to describe individuals who are not just upset, but are expressing intense feelings of anger, often in a public or noticeable way.

While "furious" is another strong synonym for extremely angry, "irate" is the term specifically recognized in more formal contexts and literature. The words "annoyed" and "upset" refer to milder forms of displeasure or disturbance and do not reflect the intensity associated with someone who is extremely angry, thus helping to confirm why "irate" is the most accurate choice in this instance.