- porcupineAny of several rodents of either of the taxonomic families Hystricidae (Old World porcupines) or Erethizontidae (New World porcupines), both from the infraorder Hystricognathi, noted for their sharp spines or quills, which are raised when the animal is attacked or surprised.
- porpoiseA small cetacean of the family Phocoenidae, related to dolphins and whales.
- porcicideThe killing of a pig or pigs.
- porcophiliaLove or admiration for pigs.
- porcophobiaA fear or dislike of pigs.