A term applied to a short man whenever he is assertive or commanding. If the exact same attitude was taken by a taller man, no one would think twice.
Tall guy steps out of a new Camaro: "Hey, check out that guy with the Camaro!, that's a sweet ride, I wonder how much he makes."
Short guy steps out of a new Camaro: "Dude, look at that little man with the Camaro, Talk about compensation!"
Tall employer assigns difficult task: "My boss gives me hard jobs, but whatever, everyone has to work."
Short employer assigns difficult task: "Damn, that prick loves to lord his authority over me! He has major Short Man's Syndrome!"