/ ˌwɔːtəˈluː; NAmE ˌwɔːtərˈluː; ˈwɑːt-/ noun
[ sing. ] sb's ~ a final defeat for sb :
This was the point at which he was to meet his Waterloo .
ORIGIN: From the battle of Waterloo in 1815, in which the British (under the Duke of Wellington) and the Prussians finally defeated Napoleon.
For more information see the Cultural Guide