When in doubt, google. I found the definition for leadership from about.com – “Leadership, a critical management skill, is the ability to motivate a group of people toward a common goal.”
I would guess that this definition is innocuous enough, but I just can’t seem to completely agree. I know that a lot of people think that leaders are great motivators. While this may be one of the by-products of leadership, I have always maintained that great leaders do not motivate others but create the environment whereby self-motivated people will be able to flourish.