Causing mental stress is an apt description for the term 'STRESSFUL, ' which is a nine-letter word. It is often used to describe situations or events that are difficult to manage and can lead to feelings of anxiety, fear, and worry. STRESSFUL situations can be caused by a variety of factors, such as work, family, relationships, finances, and health. In addition, STRESSFUL events can also be caused by external factors, such as natural disasters, political unrest, or economic instability. Regardless of the source, stress can have a significant impact on one's mental and physical health.