Definition of insecure. 1  1 : not confident or sure : uncertain feeling somewhat insecure of his reception. 2  2 : not adequately guarded or sustained : unsafe an insecure investment. 3  3 : not firmly fastened or fixed : shaky the hinge is loose and insecure.
For men, semi-formal attire means wearing a full suit, with vest optional. A tie, either bow or straight, should be worn, and the shirt should be a simple button down. Suit fabric choices are primarily wool gabardine or cashmere. However, a wool blend will do.
Semiformal Attire for Men. Men have fewer options when it comes to semi formal attire. They are required to wear a suit with a buttoned-down, collared shirt and a matching bow or necktie. The shirt should be solid or pin striped but cannot have a loud pattern. A vest is not necessary but its fine to wear.