'Pignoris arrabonisve nomine' in TPSulp. 51 (TPN 43): a case of diglossia?

Despite the fact that the term arrabo has not been attested by legal sources as nomen iuris or as a technical term, the syntagm ‘pignoris arrabonisve nomine’ occurs in a chirograph documented by TPSulp. 51, from the age of Tiberius. This article shows, first, that the loans model contract of the TPSulp. 51 contained the hendiadys ‘pignus arrabove’ to denote the pledge. Second, it concludes that the mention of arrabo is related to precautionary reasons and that it may be explained by the use of a colloquial term introduced in Latin language by way of Greek lexical borrowing. Finally, this implies some considerations on language contact, lexical interference and integration of loan-words in Latin.