A tie-pin is a small accessory that is typically worn by men to keep their ties in place. There are a number of synonyms for tie-pin, including tie clip, tie tack, cravat pin, and tie bar. While all of these terms refer to a similar accessory, they may have slightly different designs or methods of attachment. For example, a tie tack is typically a small pin with a pointed end that pierces the tie and is secured with a back piece. A tie clip, on the other hand, may have a clamp-like design that holds the tie in place without piercing it. Regardless of the term used, a tie-pin is a timeless accessory that can add a touch of style and sophistication to any formal outfit.