| Noun | 1. | Hystricidae - Old World porcupines mammal family - a family of mammals Hystricomorpha, suborder Hystricomorpha - an order of rodents including: porcupines; guinea pigs; chinchillas; etc. Old World porcupine - terrestrial porcupine Atherurus, genus Atherurus - a genus of Hystricidae genus Trichys, Trichys - a genus of Hystricidae |