FAQ: The four stages of sainthood in Theravada Buddhism

  1. sudaon, one entering the stream of enlightenment;
  2. shidagon, one who has destroyed gross evil passions and will be reborn in the human and heavenly realms once more before entering Nirvana;
  3. anagon, one who has destroyed more of his evil passions, and will not be reborn in the realm of desire (world of transmigration); and
  4. arakan (arhat), who has destroyed all his evil passions.

(Note 10, Writings of Nichiren Shōnin, Doctrine 1, Page 143)