Insecurity is a feeling of unease or anxiety about oneself, often caused by a lack of self-confidence. The term 'ANGST' is a German word meaning fear or anxiety, and is often used to describe the feeling of insecurity. Insecurity can be caused by a variety of factors, such as a lack of self-esteem, fear of failure, or feeling of inadequacy. It can also be caused by external factors, such as criticism or rejection from others. Insecurity can lead to feelings of depression, anxiety, and low self-worth.