Labour


 * Australian Labor Party
 * Communism, at least in the views of right wing bastards who can't see the difference between this and socialism
 * Giving birth to children is sometimes described as "going into labour"
 * The Labour Party
 * New Labour, Tony Blair's version of the Labour Party
 * Socialism, according to right-wingers
 * Trade unions

And, yes, the Yanks have to show that they are different from the rest of the English-speaking world by spelling it "Labor".