The term 'expression of disapproval' can be expressed in a variety of ways. The crossword solutions for this term are 'TSK' (3 letters), 'BOO' (3 letters), 'FIE' (3 letters), 'TUTTUT' (6 letters), 'BOOHISS' (7 letters), and 'REPROACH' (8 letters). 'TSK' is an interjection used to express disapproval, often accompanied by a shaking of the head. 'BOO' is a sound made to express disapproval or contempt. 'FIE' is an exclamation used to express disapproval or disgust. 'TUTTUT' is an expression of disapproval, often accompanied by a shaking of the head. 'BOOHISS' is an expression of disapproval or contempt. Finally, 'REPROACH' is an expression of disapproval or criticism.