To untie means to loosen or undo a knot or fastening. When your shoelaces are knotted together, you work to untie them by pulling and loosening the loops until they come free. When a boat is untied from the dock, someone releases the rope that was holding it in place.

The word describes reversing what tying did. If you tie a ribbon around a gift box, someone else will untie it when opening the present. If you tie a balloon to your wrist, you'll need to untie it before letting it float away.

Sometimes knots become so tight or tangled that they're very difficult to untie. A sailor might struggle to untie a knot that got wet and then dried in the sun. Your grandpa might need your nimble young fingers to help untie a particularly stubborn knot in his fishing line.

The word can also describe freeing something that was restricted: when a magician's assistant is untied after an escape trick, or when you untie your dog's leash to let them run free in the park. Anything that was bound, fastened, or secured with rope, string, or cord can be untied.