Great Satan

The Great Satan (; "Shaytân-e Bozorg") is a demonizing epithet for the United States of America in Iranian foreign policy statements. Occasionally, these words have also been used toward the government of the United Kingdom.
The term was used by Iranian leader Ruhollah Khomeini in his speech on November 5, 1979 to describe the United States, which he accused of imperialism and the sponsoring of corruption throughout the world. The speech occurred one day after the onset of the Iran hostage crisis.
Ayatollah Khomeini also occasionally used the term "Iblis" (the primary devil in Islam) to refer to the United States and other Western countries.
Background.
The post-revolutionary government of Iran has regarded the United States and the United Kingdom as imperialist states, who have a long history of interfering in Iran's internal affairs. In 1907, an Anglo-Russian agreement between Russia and Britain divided Iran into spheres of influence, ignoring, although not terminating, Iran's sovereignty. In 1953, during the Cold War, British intelligence officials and the administration of the U.S. President Dwight D. Eisenhower planned a joint Anglo-American operation to overthrow the elected prime minister, Mohammad Mossadeq. The Eisenhower administration was concerned that Mossadeq's nationalist aspirations could lead to an eventual communist takeover of Iran. The operation was code-named Operation Ajax. At first, the military coup seemed to fail, and Shah Mohammed Reza Pahlavi fled the country. After widespread rioting and with help from the CIA and British intelligence services, Mossadeq was defeated and the Shah returned to power, ensuring support for Western (chiefly British) oil interests and ending the perceived threat of communist expansion. General Fazlollah Zahedi, who led the military coup, became prime minister.
In 1965, Ayatollah Khomeini was exiled for criticizing the White Revolution's vote to women, land reform and the Shah's unpopular Status of Forces Bill, which gave U.S. military personnel diplomatic immunity for crimes committed in Iran. By the early 1970s, many Iranians opposed the Shah's government. Khomeini eventually returned to Iran and led the 1979 Iranian revolution. During the Iranian Revolution, demonstrators commonly chanted slogans such as "Death to Shah," "Independence, Freedom, Islamic Republic," and "Death to America".
Definition.
Khomeini is quoted as saying on November 5, 1979, "[America is] the great Satan, the wounded snake." The term was used extensively during and after the Islamic Revolution, and it continues to be used in some Iranian political circles. Use of the term at rallies is often accompanied by shouts of "Marg bar Amrika!" ("Death to America"). It is used in academic journals.
Lesser Satan.
Khomeini called the Soviet Union, the principal antagonist of the US during the Cold War, the "Lesser Satan" because of its atheistic communist ideology, and he said that Iran should support neither side of the Cold War.
The State of Israel was condemned as the "Little Satan" in 1979 by Khomeini when he was addressing Israel's backing of the Shah, its close ties to the US, and the ongoing Israeli–Palestinian conflict. Former Libyan leader Muammar Gaddafi also stated that "Israel is the little Satan" in a July 1980 interview.