Baretti: A dictionary of the English and Italian languages
Sódo, s. m.
1. bail, security. I danari furono staggiti che avieno per loro —, the money which they had for their security was confiscated;2. solid base, foundation, basis. Fabbricare in sul —, to build upon a good foundation. Dire o favellare in sul —, to say or speak any thing in earnest or seriously. Porre or mettere in —, to purpose, resolve, determine, deliberate. Così la pace si metteva in —, so they were deliberating upon the peace; 3. barren or uncultivated land.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
sodo: solide, tough, fast, hard, stiffe. Also a strong shore or vpholder of stone or timber. Vsed for the essentiall bodie or substance of any thing.