swine: [OE] Swine is the ancestral English term for the ‘pig’, and it remained the main word until pig began to take over from it in the early modern English period. It came from a prehistoric Germanic *swīnam, which also produced German schwein, Dutch swijn, and Swedish and Danish svin. And this in turn went back to Indo-European *su-, source also of English hyena and sow. => hyena, sow
swine (n.)
Old English swin "pig, hog, wild boar," from Proto-Germanic *swinan (cognates: Old Saxon, Old Frisian Middle Low German, Old High German swin, Middle Dutch swijn, Dutch zwijn, German Schwein, Old Norse, Swedish, Danish svin), neuter adjective (with suffix *-ino-) from PIE *su- "pig" (see sow (n.)). The native word, largely ousted by pig. Applied to persons from late 14c. Phrase pearls before swine (mid-14c.) is from Matt. vii:6; an early English formation of it was:
Ne ge ne wurpen eowre meregrotu toforan eowrum swynon. [c. 1000]
The Latin word in the Gospel verse was confused in French with marguerite "daisy" (the "pearl" of the field), and in Dutch the expression became "roses before swine." Swine-flu attested from 1921.
