tailfan
/ˈteɪlˌfæn/
noun
- A fan-shaped structure at the rear of an animal, especially the tail feathers of a bird or the tail fin of a fish.
- The bird's tailfan was damaged, so it had trouble balancing on branches.
- The fish's tailfan helps it steer quickly through the water.
- The peacock spread its colorful tailfan to attract a mate.