abolition. Total elimination, versus the reform, of some form of oppression, enslavement, or abuse (HumaneMyth.org).

animal advocacy. Promotion of the interests of animals, generally. Includes work for animal rights and animal welfare.

Animal Enterprise Terrorism Act (AETA). Federal law fast-tracked through Congress in 2006 that severely restricts freedom of speech and assembly and labels as terrorism any act that so much as "interferes" with businesses that deal with or profit from animal use or animal products.

Animal Liberation Front (ALF). Name used by individuals who independently carry out direct actions on behalf of animals, such as the covert rescue of animals from research labs. Property destruction intended to prevent or impede future harm to animals or to economically weaken animal-exploiting industries is frequently involved. There is no membership, no leadership, and no structure to the ALF (see the ALF Credo and Guidelines).

animal rights. Refers to the position that the interests of nonhuman animals, including their interest in not suffering, should be afforded the same consideration as the interests of humans and that nonhuman animals have rights and inherent value independent of their usefulness to humans.

animal welfare. Refers to the well-being and treatment of animals. The animal welfare position objects to what it considers unnecessary suffering and seeks to improve treatment of animals, but it does not object to animal use generally or to harm it considers necessary or justifiable.

backyard breeding. The practice of keeping one or more animals (usually dogs but including cats) for the purpose of breeding them, usually for profit, or the practice of allowing the animal to breed (rather than having the animal spayed or neutered).

battery hens. Hens used for egg production who are confined, several birds at a time, to cramped, dark cages and sent to slaughter when their egg production declines See battery cage and forced molting.

battery cage. Small wire cage, stacked among thousands of other cages, inside a large, windowless shed and containing several chickens each. Battery cages afford the animals not even enough room to stand, move about, or spread their wings. Each hen's individual space is smaller than a sheet of notebook paper. See debeaking and forced molting.

broiler chicken. The term used for chickens raised and slaughtered for meat. They grow twice as fast as their bodies were naturally designed to, so fast that their hearts, lungs, and legs cannot support their bodies.

bullhook. Also called an ankus or elephant hook, a cruel so-called tool used to brutalize and control elephants in circuses.

CAFO. Confined animal feeding operation. See factory farming.

cage-free. A term used mostly for the marketing of eggs. The term is not regulated and does not guarantee so-called humane treatment. Most birds in operations labeled as cage-free still suffer the same injuries, cruelties, and disregard as their counterparts on factory farms. See debeaking.

castration. The act of cutting off a male animal's genitals. Bull calves, piglets, and other animals endure this excruciating mutilation without any painkillers.

cognition. Refers to mental processes such as consciousness, intelligence, self-awareness, thought, and decision making. See sentience.

commodification. The conversion of a living being, principle, or natural environment into an "object" that is used, exchanged, or consumed for profit or other desired gain (HumaneMyth.org).

companion animal. Term referring to the animals with whom humans most commonly share their lives and homes—for example, dogs, cats, and rabbits. Preferred by many animal advocates to the word "pet."

cruelty-free. A term used to refer to products and practices that eliminate intentional cruelty and harm. For example, personal care products that contain no animal ingredients and that are not tested on animals may bear a "cruelty-free" label or emblem, such as the Leaping Bunny logo.

debarking. The surgical removal and manipulation of tissue in a dog's vocal cords to drastically quiet his or her natural bark. Debarking does not address the underlying reasons that a dog may be barking excessively, and the dog will continue to bark, albeit more quietly or silently. Illegal in the United Kingdom, it is still allowed in the United States.

debeaking. The mutilation of a young bird's beak. The days-old chick or weeks-old turkey is held tightly while a hot guillotine-like blade is used to slice off one-third to one-half of the bird's beak, through horn, bone, and highly sensitive tissue. The severe immediate pain persists even following the mutilation, which also permanently hinders the bird's ability to properly eat, drink, and preen.

declawing. The surgical removal of a cat's claws, in a painful procedure akin to cutting off toes up to the first knuckle. Recovery is painful as well, given that the cat must continue to walk on and use the litter box with freshly operated-on paws. Illegal and considered inhumane in the United Kingdom and other European countries, it is still a common practice in the United States.

direct action. A general term referring to various forms of protest and activism, ranging from protests to boycotts to leafleting to the covert or open rescue of animals (on the latter topic, see Animal Liberation Front and open rescue).

dissection. The practiced of cutting open or into a dead animal or separating the parts of the animal to examine the tissue and internal structure. It is still common in secondary schools and colleges, but students are increasingly voicing their opposition and demanding alternatives.

Draize test. Infamous and excruciating eye-irritation test for household products and cosmetics in which drops of a substance are placed in the eyes of rabbits, causing the animals ulcers, blindness, and other injuries before they are ultimately killed.

ear cropping. An unnecessary, painful cosmetic surgery performed on dogs in which a large part of the earflap is cut off to make the ear stand erect. Illegal in the United Kingdom and other countries but still legal and common in the United States.

exploitation. The use—often harmful or unfair—of another being for one's own advantage or pleasure (e.g., for food, clothing, research, and entertainment in the case of animals).

euthanasia. The killing, or the allowance of the death of, a being out of mercy and for the sake of the animal, when that being is "hopelessly sick or injured." Imprecise, euphemistic use of the term to refer to the killing of healthy animals is controversial.

factory farming. The industrial, large-scale system of meat, dairy, and egg production in which extreme confinement and the most inhumane of animal cruelties are standard.

flank strap. A strap pulled tightly and painfully around a rodeo horse's sensitive abdomen just as the chute opens, to force the horse into bucking, as the horse tries to escape the pain and discomfort caused by the strap. Also known as a bucking strap.

foie gras. Translated literally as "fatty liver" and served as a delicacy, foie gras is the result of immense cruelties. Young ducks are force-fed massive of amounts of food two to three times a day through metal pipes shoved down their throats. In a few short weeks, the livers of these sick, tortured animals have grown to 10 times their normal size, at which time the ducks are slaughtered and their livers sold for consumption.

forced molting. The egg-industry practice of artificially inducing hens to molt by depriving them of food for several days to two weeks when their egg production has declined. Following the molting, egg production increases.

free-range. A description and label applied to certain chicken and egg farms that many assume ensures some kind of natural, happy life for the animals. In reality, "free range" is not a well-regulated label, and most of these animals still suffer in confined, poor conditions for most or all of their lives. See cage-free.

gestation crate. Small metal crate in which a mother pig spends almost her entire adult life, with not enough room to even turn around.

hatchery. Virtually all chickens raised and killed for eggs, including those at so-called humane operations, come from hatcheries. At only a day or two old, half of the chicks born at hatcheries are ground up alive, gassed, or thrown alive into trash bags, where they suffocate to death: male chicks, who cannot produce eggs, and deformed female chicks are useless to the egg industry.

hunt sab. Intentional sabotage of an organized hunting expedition by such means as alerting the animals with horns, masking the pursued animals' scent or creating noise and distractions when humans are using hounds to track the animals, and engaging in patrols to document and thwart illegal hunting attempts.

mulesing. The wool-industry practice of slicing large chunks of flesh from around the sheep's tail area, for the purpose of managing flystrike (which results from flies laying eggs in the moist folds of the sheep's skin), without any anesthesia or painkiller.

no-kill. Refers to the movement for no-kill policies and shelters, where only unadoptable animals or those unable to be rehabilitated are killed.

open rescue. A rescue of animals conducted openly, without masks or other efforts to hide identity. Open rescue efforts seek to document cruelties, publicize, and educate in addition to rescuing animals in need.

puppy mills. Large-scale dog-breeding operations notorious for their substandard care and cruelties, including overbreeding, overcrowding, lack of veterinary care, and inadequate food and shelter. Puppy mills sell through pet stores, Web sites, and advertisements.

rape rack. The brutal, but accurate, industry term referring to the contraptions in which cows and pigs are restrained while they are forcibly inseminated.

sentience. The ability to experience pain, pleasure, and other sensations; the capacity to suffer. Chickens, pigs, cows, rabbits, dogs, cats, rats, monkeys, and elephants, for example, like the majority of other animals, are sentient.

silk. A liquid substance produced by silkworms that hardens upon contact with the air and forms the silkworm's cocoon. So that humans can retrieve the intact silk thread that makes up the cocoon (i.e., before the silkworm breaks the cocoon to emerge), the silkworms are boiled, baked, or steamed alive while still inside their cocoons.

speciesism. Discrimination on the basis of species; oppression and judgment of an animal on the basis of that animal's species or that animal's non-membership in a species. The belief in human superiority over other animals or certain nonhuman animals' superiority over others.

spent. An industry term for egg-laying (battery) hens and dairy cows whose egg and milk production has declined enough that they are no longer profitable. Spent hens and cows are sent to slaughter at a fraction of their natural lifespan.

stereotypic behavior. Repetitive behaviors commonly seen in captive animals and likely induced by stress and lack of appropriate stimuli (e.g., overgrooming among primates, pacing among tigers, and the swaying of elephants).

tail docking. Among dogs, the surgical amputation of the tail, usually for cosmetic reasons. The tails of pigs are docked because the stress and boredom of their lives in confinement can lead to tail-chewing.

utilitarianism. An ethical philosophy in which moral decisions are based on the utility of an action. In this line of thinking, human and nonhuman interests are afforded the same value, but an act harmful to an animal is permissible if the benefit to the human is greater than the cost to the animal. Utilitarianism bears more similarities to animal welfare than to animal rights.

veal. The culinary term for the flesh of a young calf and a byproduct of the dairy industry. Calves are taken from their mothers (dairy cows) shortly after birth, confined, and placed on a formula or other substandard diet until they are slaughtered at 5 to 6 months of age. Humans consume the mother cow's milk. See veal crate.

veal crate. Small crate in which a calf being raised for veal is confined and tied up. The calf's movement within the crate is intentionally restricted to limit the strengthening of muscle, and an insufficient diet is provided intentionally to keep the cow anemic: veal is preferred tender and pale in color. See veal.

veganism. As defined by the Vegan Society, the founders of which coined the term: "a philosophy and way of living which seeks to exclude—as far as is possible and practical—all forms of exploitation of, and cruelty to, animals for food, clothing or any other purpose; and by extension, promotes the development and use of animal-free alternatives for the benefit of humans, animals and the environment. In dietary terms it denotes the practice of dispensing with all products derived wholly or partly from animals." Vegans do not consume meat, dairy, eggs, or other animal byproducts; do not wear clothing derived from animals, such as leather, fur, and wool; and do not use products containing animal ingredients.

vegetarianism, lacto-ovo. A diet that excludes meat (including beef, poultry, and fish) but that includes dairy and eggs. Vegetarians may or may not still use clothing and products derived from animals.

veg*n or veg*an. An inclusive term referring to the categories of lacto-ovo vegetarians and vegans together.

vivisection. Cutting or operating on a live animal. The term also refers more generally to experimentation on animals for medical research and product testing. Vivisection includes the cutting, burning, infecting, drugging, starving, blinding, and killing of animals for research, for the testing of drugs and treatments, and for the testing of consumer products, such as cleaners, food additives, and cosmetics.