diaper

A diaper is a special kind of cloth used for babies to wear on their bottom.

You've probably seen them before - they're those absorbent things that parents use to change their baby's diapers all the time. It's not just about the changing, though - it's also about making sure the baby stays clean and dry. When you hear someone say "diaper", they usually mean one of a few things: either a disposable pad that absorbs wetness, or a cloth diaper (also called a nappy) that can be washed and reused.