lepsy (plural lepsies) is a lemon and pepsi infused together makeing the flavor 80% lemon, 20% pepsi. Sour? yes, but delightful for people that can handle it. The citrus from the lepsy makes your stress levels lower, and since it is only 20% pepsi, it is very low cal.
A lepson is a person who copies anything you say. If you have a new catch phrase or a great idea, a lepson will come along and think they are really cool when they steal it and use it as if its their own.
A lepson then, is a very annoying copycat type try hard that makes you want to smash them in the face.