(noun) - Orientalism is a style of art associated with a group of 19th-century artists who were fond of depicting harem girls, sheikhs and Middle-Eastern scenery - whether or not the artist had actually spent time in the Middle East. Delacroix, Ingres and (Henri) Rousseau - to name the three best-known artists - all employed "oriental" touches to various works.
Orientalism, as a phrase, was first coined in the political discourse of Edward Said (in Orientalism, New York: Vintage, 1979). Here, Said argued that Eurocentrism had done a great disservice to Middle-Eastern (i.e.: non "white") culture. (There was much more to the discourse, in the vein of colonialism and non-Occidentalism. It's probably better suited to a sociological discussion than one regarding art history, though.)