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.
Semi-Formal: Black Tie. This black tie has peak lapels, but they are also cut in shawl collar: If the invitation says Black Tie, it's semi-formal. It if says,Black Tie Optional, Black Tie Welcome, Cocktail Attire and the event is in the evening, black tie is encouraged.