Princeton's WordNet

1. John, Saint John, St. John, Saint John the Apostle, St. John the Apostle, John the Evangelist, John the Divine(noun)

   (New Testament) disciple of Jesus; traditionally said to be the author of the 4th Gospel and three epistles and the book of Revelation

2. Saint John, Saint John River, St. John, St. John River(noun)

   a river that rises in Maine and flows northeastward through New Brunswick to empty into the Bay of Fundy

3. Saint John, St. John(noun)

   a port in eastern Canada; the largest city in New Brunswick