Batman is, of course, the name for a military officer's servant. The term derives from the old word bat meaning a packsaddle. In America, where they're far more logical about such things, the equivalent position is referred to as a dog-robber.
Batman is, of course, a unit of measurement found in Asia. Batman has varied wildly in value over the centuries and was finally redefined as 10kg when Turkey basted itself with the metric system.
Batmania is, of course, the original name of the Australian city of Melbourne. John Batman, a syphilitic farmer from Sydney, persuaded some of the natives to lease some land to him for an annual rent of two hundred handkerchiefs, a hundred knives, a hundred pounds of flour, fifty scissors, forty blankets, thirty mirrors, thirty axes and six shirts. He then named the new settlement after himself: Batmania.
The rent was clearly exorbitant and the governor cancelled it a few years later, shot anyone who disagreed, and renamed the town Melbourne after the Viscount Melbourne who was prime minister at the time.
Batmania isn't as mad as it sounds to our surprised ears. After all, Tasmania is named after Abel Tasman.
There are no other known meanings of the word batman.
Became a hat-man.
He said, "It's rainier