A "sour expression" refers to a facial look that conveys displeasure, annoyance, or disapproval. It often includes features such as a furrowed brow, pursed lips, and narrowed eyes. This expression can be a reaction to unpleasant tastes, situations, or interactions, signaling discomfort or dissatisfaction. People may display a sour expression in various contexts, such as during a disagreement or when tasting something unpalatable. It serves as a non-verbal cue, helping others understand that the individual is not pleased. Recognizing a sour expression can enhance communication and empathy in social situations.