A rival or opponent who seems unbeatable; deserved or retributive justice or punishment, an avenger, a source of harm.
The bourgeois world was haunted by sex, but not necessarily sexual promiscuity: the characteristic nemesis of the bourgeois folk-myth, as the novelist Thomas Mann saw so clearly, followed a single fall from grace, like the tertiary syphilis of the composer Adrian Leverkuehn in Dr Faustus.
E.J. Hobsbawm, The Age of Capital 1848–1875.
For weeks they had been told that Lord Hutton's findings would be the nemesis of the Prime Minister and the Secretary of State for Defence.
That is the danger that we are now facing. It is that too many members of the Cabinet led by the member for Ku-ring-gai are governed by hubris, which is defined in the Oxford Dictionary as "insolent pride or presumption - leading to nemesis". In the previous debate on the Metherell affair I said that it had the elements of a Greek tragedy. As the weeks have turned to months it has inevitably led to the nemesis of the previous Premier and the previous Minister for the Environment. The events of the past week have been tumultuous and cataclysmic, and the inevitable nemesis that comes to those afflicted by hubris is now upon them.
Elisabeth Kirkby, New South Wales Hansard, 30 June 1992. NSW Hansard
Royal Bank of Scotland chief executive Fred Goodwin yesterday hit out at last week's warning from Barclays that a quarter-point rise in interest rates would be "financial nemesis for some people".
James Moore, Telegraph, 22 September 2005. Telegraph