What it is: This innocent-sounding expression refers to an atrocity: the use of force (including killing and destruction of property) or intimidation (including threats and humiliation) to drive people of a particular ethnic group away from a particular area.

What it means: 'Ethnic' comes from a Greek word meaning 'race'. Many people readily gather into groups that have characteristics in common. What holds them together could be their race or clan, their religion, their language, or their culture and customs. Within the population of a nation, ethnic communities are often minority groups, and may well become victims of prejudice and discrimination. Whether their ethnic group is large or small, the people in it are protective of the things that unite them, and they can easily feel threatened by outsiders. Sometimes they are right to feel that. During the civil war in Bosnia, which began in 1992, Serbian forces drove Muslims out of several areas, and killed many thousands of them. They also forced other non-Serbs and Croats out of their homes. Some Muslims and Croats also tried to 'cleanse' their own neighbourhoods of Serbs in the same brutal way This kind of conflict is not new: there have been examples throughout world history. But it has been a particularly terrible feature of the 20th century. The Nazis used these tactics in the Second World War, targeting Jews, Gypsies, and other groups whose race or religion they hated. In Rwanda in 1994, the Hutu majority 'ethnically cleansed' parts of the country by attacking and murdering the ruling minority Tutsis (and any Hutus suspected of taking the Tutsis' side).

Think about it: People talk of how human beings have become 'civilised'. But, as one observer puts it, 'the forcible expulsion of rival ethnic groups has become the measure of the breakdown of civilised values'. What, in your opinion, are civilised values? What threatens them, and how can they be protected?