Clucks of disapproval are a form of nonverbal communication used to express disapproval or dissatisfaction. The term 'clucks of disapproval' is often used to describe the sound made by a person when they are unhappy with something. The crossword solutions for this term are TUTS (4 letters), TSKS (4 letters), and TUTTUT (6 letters). TUTS and tsks are both onomatopoeic words that imitate the sound of clucking, while tuttut is an interjection used to express disapproval.