A moneybox is a small box, tin, or little container that children put coins in to save them. In British English this is the ordinary word; many families also say piggy bank when the box is shaped like a pig. The idea is the same: you drop money in and you are not supposed to take it out every five minutes. Though actually, a moneybox need not look like a pig at all — it can be a tin with a slot, a wooden box, or a plastic toy. Adults use the word too, a little fondly, for that childhood saver. It is not a bank account and not a cash register. American English leans toward piggy bank and less often uses moneybox. You may also see it written as two words, money box.