swordtail
/ˈsɔːrdteɪl/
noun
- A small tropical freshwater fish, popular in home aquariums, with a long, pointed tail fin that looks like a sword.
- My son's aquarium has a bright orange swordtail swimming among the plants.
- The male swordtail is easily recognized by the long extension on its tail.
- Swordtails are easy to care for, making them a good choice for beginner fish keepers.