To overcharge means to ask for more money than something is actually worth or more than was agreed upon. When a store overcharges you, they charge you $15 for something that should cost $10. When a repair shop overcharges for fixing your bike, they might bill you $50 when the fair price should be $30.

Overcharging is different from something simply being expensive. An expensive restaurant might charge $40 for a steak, and while that's a lot of money, it's not overcharging if that's the posted price and you get what you paid for. But if that same restaurant adds extra items to your bill that you never ordered, or charges you $50 when the menu clearly said $40, that's overcharging.

Sometimes businesses overcharge by accident, like when a price doesn't ring up correctly at the register. But deliberate overcharging is a form of dishonesty. It takes advantage of customers who trust that they're being charged fairly.

The word can also mean putting too much electricity into a battery, like overcharging a phone by leaving it plugged in too long, though modern devices usually prevent this automatically.