Someone who has successfully conquered, subdued, or otherwise come into control of the entire planet. It is a difficult, if not impossible to attain position; one that generations of leaders have been attempting.
The first one who looked like they might pull it off was Napolean. Then he invaded Russia... now he's a cameo in a movie about time-travelling rock stars. The second one who might have pulled it off was Hitler. He too made the mistake of invading Russia.
The two present-day advocates seem to be tied between Bill Gates, Chairman of Microsoft, and Orin C. Smith, President, Chief Executive Officer and Director of Starbucks Coffee. Both of which have invaded Russia with varying degrees of success.
World Dictators are typified by being unusually arrogant, having troops dressed in very neat outfits (and are yet unable to shoot a hero at 20 feet), and having something of a God Complex. They usually start very small, then appear to come from nowhere, somehow discreetly incorporating their henchmen into mainstream life, until such time as they have become a mega-power and are virtually unstoppable.
Seattle, Washington's main export has evolved into small family businesses that grow suddenly, appearing to come from nowhere, placing themselves into the bloodstream of the consumerate, and finally devouring any other remotely similar bussiness in it's path. (Examples: Starbucks, Microsoft, Barnes and Noble, Real Networks, Amazon.com) It is thusly believed that there is a darker power at work in Seattle, controlling the other companies like a puppetmaster...