What is Determinate?

Legal Definition
That which is ascertained; what is particularly designated; as, if I sell you my horse Napoleon, the article sold is here determined. This is very different from a contract by which I would have sold you a horse, without a particular designation of any horse. 1 Bouv. Inst. n. 947, 950.
-- Bouviers Law Dictionary
Legal Definition
That which is ascertained; what is particularly designated.
-- Black's Law Dictionary
Legal Definition
Made certain.
-- Ballentine's Law Dictionary