What is Debitor Non Praesumitur Donare?

Legal Definition
A debtor is not presumed to make a gift. Whatever disposition he makes of his property is supposed to be in satisfaction of his debts. 1 Karnes, Eq. 212. Where a debtor gives money or goods, or grants land to his creditor, the natural presumption is that he means to get free from his obligation, and not to make a present, unless donation be expressed. Ersk. Inst. 3, 3, 93.
-- Black's Law Dictionary
Legal Definition
A debtor is not presumed to give.
-- Ballentine's Law Dictionary