The term 'angry crowd noise' can be summarized by two crossword solutions: OUTCRY (6 letters) and SSS (3 letters). OUTCRY is a noun that refers to a loud, emotional expression of protest or pain. It is often used to describe the sound of a large group of people expressing their anger or frustration. SSS is an onomatopoeia that is used to represent the sound of a crowd booing or hissing in disapproval. It is often used to describe the sound of a large group of people expressing their dissatisfaction with something.