To bring together so as to form a whole. To combine (people) in interest, attitude, or action: "the love that unites humanity\u201d ( Germaine Greer). To join (a couple) in marriage. To cause to adhere. To have or demonstrate in combination: She unites common sense with vision. To become or seem to become joined, formed, or combined into a unit. To join and act together in a common purpose or endeavor. See Synonyms at join. To be or become bound together by adhesion.