The word "upset" generally refers to a feeling of being troubled, distressed, or emotionally disturbed. It can describe various negative emotions, such as sadness, anger, or frustration, often due to an unexpected or unwelcome situation or event.
The word "upset" comes from the Middle English "upsetten," which means to overturn or overturn something. It combines "up," meaning in a higher position, with "set," suggesting to place or position. Over time, its meaning expanded to include emotional states and disturbances.