Black's Law Dictionary (2nd edition)dictionaries

Facio Ut Des

(Lat. I do that you may give.) A species of contract in the civil law (belng one of the innominate contracts) whlch occurs when a man agrees to perform anythlng for a prlce elther specifically mentioned or left to the determination of the law to set a value on It; as when a servant hires hlmself to hls master for certaln wages or an agreed sum of money. 2 BL Comm. 445

Source: Black's Law Dictionary 2nd Ed (1910)