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.
The Basics. Attending a semi-formal or cocktail event used to mean dresses only for ladies. Nowadays sleek separates like dress pants and skirts can also be appropriate semi-formal attire. Stick with something in a luxe fabric, like jacquard, lace or chiffon.