Giaour or Gawur meaning "infidel", is slur used mostly in the lands of the former Ottoman Empire for non-Muslims or, more particularly, Christians in the Balkans.
Théodore Géricault: The Giaour (1820, lithograph; Metropolitan Museum of Art, New York)
Eugène Delacroix: The Combat of the Giaour and Hassan (1826, oil on canvas; Art Institute of Chicago), inspired by Lord Byron's The Giaour
Giaours smoking the tchibouque with the pacha of the Dardanelles, book illustration from 1839.
Kafir is an Arabic term in Islam which refers to a person who disbelieves the God in Islam, denies his authority, rejects the tenets of Islam, or simply is not Muslim and does not believe in the guidance of the Islamic prophet, Muhammad.
The Kafirs of Natal and the Zulu Country by Rev. Joseph Shooter