This article discusses the attestations and etymology of Greek σίαλος ‘hog’. The word can be shown to be almost entirely limited to the earliest attested stages of the Greek language. Both Mycenaean and Homeric Greek suggest that the word was strongly adjectival in origin and not at first limited to denote pigs. The Indo-European etymologies advanced are either formally difficult or semantically unconvincing. On palaeographic as much as linguistic grounds the word is traced back to Linear A, and it is argued that it was borrowed from there into Greek as a technical agricultural term.