These words denote a domestic mamma whose flesh, called pork, is used as food in most countries of the world. Pig is the most general term: to raise pigs for the market. A small pig, weighing up to 130 pounds live weight, is called a pork pig , and one between 130 and 240 pounds live weight a bacon pig . Other terms exist for pigs weighing more than 240 pounds (such as backfatter), but these are confined mostly to farmers and other engaged in the meat industry. Hog is a common synonym for pig in the United States, where it refers specifically to an animal weighing more than 120 pounds. The word is not used in a commercial sense in Australia or New Zealand, but because of the association of both hog and pig with a voracious appetite, both words are commonly used to describe a greedy or gluttonous person. Hog is a more abusive term than pig , which is often intended half-humorously. The term road-hog also illustrates the pejorative use of the word.

Swine , which is also a collective noun, has been largely supplanted by pig or hog and now has a somewhat literary sound: Circe, who turned men into swine ; a courtesan of kings, who tended swine as a child. Swine is still applied to a person and is more insulting than either pig or hog because it implies not only greed but viciousness and depravity.

A boar is an uncastrated male pig of any domestic breed. It applies also to a wild pig of either sex which is hunted for sport in Australia, new Zealand, continental Europe, southern Asia, North Africa and formerly in England. Sow is the correct term for a female domesticated pig used for breeding. Figuratively, sow is used contemptuously to describe a fat coarse, slovenly woman.

Porker is applied to a pig or hog that is being fattened for slaughter. A sucking-pig is the same but is much younger and is considered a great delicacy. Porker is also a humorous term for any pig or hog .