If something uncoils or if you uncoil it, it becomes straight after it has been wound or curled up. If someone who is curled up uncoils, they move so that their body becomes straight. He uncoiled the hose and gave them a thorough drenching Dan played with the tangerine peel, letting it uncoil and then coil again Mack seemed to uncoil slowly up into a standing position. if you uncoil something, or if it uncoils, it stretches out straight after being wound around in a circle