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puerco (Adjective, Noun) "dirty;" "hog"
11th cent. From Latin porcus 'id.' From Proto-Italic *pork-o- 'id.' From Proto-Indo-European *pórḱ-o- "pig," but originally "digger."
Also in the feminine meaning "slut."
Indo-European
Romance
Asturian puercu, Portuguese porco, Galician porco, Catalan porc, French porc, Italian porco, Aromanian porcu, Romanian porc, Sardinian porcu
Italic
Umbrian purka "sow"
Celtic
Old Irish orc "pig"
Germanic
Old High German farah "pig," Old English fearh 'id.' (English farrow)
Balto-Slavic
Church Slavic prasę "piglet," Russian porosja 'id.,' Czech prase 'id.,' Polish prosię 'id.,' Slovene prasè 'id.,' Old Prussian prastian 'id.,' Lithuanian par̃šas 'id.'
Armenian
Armenian ors "hunt"
Indo-Iranian
Avestan parəsa- "piglet"

"IE *porko- (Latin porcus) denotes the domestic pig as opposed to the wild animal, *sū- (Lat. sūs); The dialect distribution of *porko- leads to the conclusion that only the European tribes practiced pig-breeding.

However, a careful examination shows 1) that in all languages, and particularly in Latin, where the opposition *sū- : *porko- was maintained, both these terms applied to the domesticated species, *porko- designating the piglet as opposed to the adult *sū-." ~ E. Benveniste, Indo-European Language and Society (1973)