To furl is to roll something up, the way you furl your sleeping bag before sliding it into your backpack on a camping trip.
Furl comes from roots meaning "to hold firmly" and "to bind." It's frequently used when sailors take down sails and roll them securely: "Furl the main sail! There's a storm brewing!" You can also use it for a leaf or flower that's curled up, as opposed to unfurled: "Those blossoms furl at night and open in the daytime." Or, if you want to show off your vocabulary, you might say: "Let me just furl these burritos and then we can eat."