Okay kiddo, a Lancaster pistol is a type of gun that was made a long time ago, during the 1800s. It's named after a city in England called Lancaster.
Now, you know how some guns are big and heavy and hard to carry around? Well, a Lancaster pistol is different because it's smaller and lighter. It's also easier to use because you can hold it with just one hand!
People used to use Lancaster pistols for things like hunting or protecting themselves. But, they're not really used that much anymore because there are newer and better guns available.
That's pretty much it, kiddo. Remember to always stay safe and never play with guns!