The word "threepiecer" has several synonyms that can be used depending on the context or situation. Some common synonyms for "threepiecer" include a three-piece suit, suit and tie, formal attire, or business dress. These terms are often used to refer to a standard formal or professional outfit consisting of a jacket, vest, and pants. Other synonyms for "threepiecer" might include a smart ensemble, dressy outfit, or even a power suit. These synonyms can all be used to describe the same type of formal or professional attire, although they may carry slightly different connotations or levels of formality.