Swine comes from Old English swīn ('pig'), from Proto-Germanic *swīną, from Proto-Indo-European *suH-ino- ('belonging to the pig'), an adjectival derivative of *suH- ('pig, swine'). The historical chain includes Old English swīn and Proto-Indo-European *suH-. The quoted older senses, "pig", "belonging to the pig", and "pig, swine", supply the semantic anchors for swine. The formation is best read as borrowed: the word swine carries its older form-history into a compact English lexical shape. In present English it is used as a noun, "a pig or pigs; a contemptible person". English derivatives include swineherd and swinish; related English forms include sow. The result is a noun whose etymology preserves both the older form and the later English specialization.