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.
A semi-formal evening wedding is just slightly dressier than a semi-formal daytime wedding, but you can wear the same thing to both. A cocktail dress and heels or dressy separates (same as daytime) will look great but don't forget that an LBD is also an excellent option for a semi-formal evening ceremony.