The term LOOK SULLEN can be broken down into four crossword solutions: LOUR, POUT, MOPE, and LOWER. LOUR is a verb meaning to scowl or frown, while POUT is another verb meaning to express displeasure by protruding the lips. MOPE is a verb meaning to be listless or depressed, and LOWER is a verb meaning to make or become less in amount, degree, or intensity. All of these words describe a person who looks sullen, which is a facial expression that conveys sadness, disappointment, or anger.