A swine is a pig or a big ol’ nasty hog. Swine have short legs, thick bodies, and they eat just about anything. If someone acts like a pig, call him a swine.
Although it’s old fashioned, the word swine comes in handy if you need another word for hog, like if you’re really into writing poems about pigs. Swine — which is also the plural form, like fish — are common farm animals. Some are eaten as bacon, some are kept as pets. Swine themselves are omnivorous, so they'll eat meat, vegetables, or, well, garbage.