Trigamy is a term that refers to the state of having three spouses at the same time. However, there are several synonyms that are used to refer to this practice. One synonym for trigamy is triple marriage. Another term that is used to describe the same phenomenon is polygamy, which means having multiple spouses. Some people may also use the term polygyny to refer to the practice of having multiple wives at the same time. Other synonyms for trigamy include polyandry, which refers to the practice of having multiple husbands, and group marriage, which involves sharing a marital relationship among more than two people.