It originally was duck tape, as it was designed for use on military vehicles called ducks. Ducks have tires to drive on land and a motor to travel on water. They drive into water, use the on board motor to boat around and drive out the other side. They needed something waterproof to patch holes and duck tape was born.

It wasn’t until after WW2 that people started using it for ducts and then people started calling it duct tape.