The phrase "set three" can be substituted with several synonyms to enhance clarity or rephrase meaning. One alternative term is "group of three," which straightforwardly specifies three entities that belong to the same category or exhibit a common trait. Another option is "trio," which denotes a musical ensemble or a team of three performers. "Triptych" is a synonym that applies to a painting or a photograph composed of three distinct parts arranged side by side or vertically. "Triad" is another synonym that characterizes a group of three individuals or concepts, often used in the context of philosophy or religion. Lastly, "threesome" can be used colloquially to describe a sexual encounter involving three individuals.