A bundle is a package of things wrapped together. To wrap things together in a compact way is to bundle them. A baby wrapped up in a blanket is a bundle of joy, and if it’s cold outside, bundle up!
Bundle comes from the Middle Dutch word for bind, which is what you do when you bundle stuff — you bind it together. It also means to wrap in warm clothes. This is a word for things that are tightly packed together. If you get a package in the mail, it's a bundle. If you have knickknacks all over the place, you'll need to bundle them when you move by putting them in a box.