noun

• 1A newly established frontier, especially (in U.S. History) one marking a westward expansion of pioneer settlement. Later also: a region offering new opportunity, especially one which is unfamiliar.

• 2In extended use. Generally. Anything which marks or indicates the limits of the present state of knowledge, policy, etc., especially as a starting point for new work; a new challenge; a new development.

• 3US Politics
  historical In form New Frontier. A programme of social improvement advocated by John F. Kennedy, President from 1961 to 1963.