's map of the new world, first published in 1540
the new world is one of the names used for the majority of earth's western hemisphere, specifically the americas (including nearby islands), and oceania. the term originated in the early 16th century after europeans made landfall in what would later be called the americas in the age of discovery, expanding the geographical horizon of classical geographers, who had thought of the world as consisting of africa, europe, and asia, collectively now referred to as the old world (a.k.a. afro-eurasia). the phrase gained prominence after the publication of a pamphlet titled mundus novus attributed to italian explorer amerigo vespucci. the americas were also referred to as the "fourth part of the world".