Threeness is a word that describes the quality or state of being three. In order to express this concept using different words, one could use synonyms such as "trinity", "triplet", "triumvirate", "trefoil", "triad", or "threesome". Each of these words has a slightly different nuance in meaning, but all are used to convey the notion of a group or set of three. Whether referring to elements in a design, people in a relationship, or parts of a whole, these synonyms can be used to add variety and precision to one's language.