| Noun | 1. | Erethizontidae - New World arboreal porcupines mammal family - a family of mammals Hystricomorpha, suborder Hystricomorpha - an order of rodents including: porcupines; guinea pigs; chinchillas; etc. New World porcupine - arboreal porcupine Erethizon, genus Erethizon - a genus of Erethizontidae |