The crossword solution for the term 'Piggy-Bank Aperture' is 'SLOT', which is a four-letter word. A SLOT is an opening or aperture in a container, such as a piggy bank, that allows coins or other items to be inserted. It is typically a narrow opening that is designed to prevent items from being removed without breaking the container. Piggy banks are traditionally used to save money and are often given to children as a way to teach them about saving.