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.
1 Cotton or jersey fabric is perfect for a semi-formal dress.  Dress up when in doubt. Thereâs a lot of grey area in what is expected for a semi-formal event. In any case, itâs better to overdress for an occasion than to underdress for it.