A plum is a sweet and tart fruit that grows on a plum tree. It's a fruit that come in a wide variety of colors, flavors, and sizes. They are a drupe, which means that they have a fleshy outer layer that surrounds a single hard pit.

Examples:

1. My mom made a plum cake, and the sweet smell filled the kitchen.
2. My sister's favorite shade of lipstick was a deep, rich plum color.
3. I'm going to my neighbors house to help make the plum jam.