Quatrefoil is a fancy word for a shape that has four roundish parts that look like leaves or petals. Imagine drawing a square, but the corners are all rounded to look like little circles. If you connect the middle points of each circle, you end up with a pretty shape that resembles a four-leaf clover or flower. Quatrefoils are often used in fancy designs for buildings, furniture, and decorations because they look elegant and symmetrical. It's a bit like having a special sticker or badge with four pretty shapes in it. It's also fun to try drawing a quatrefoil on paper and coloring it in to make a pretty design of your own!