Simple contract debt
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
One where the contract upon which the obligation arises is neither ascertained by matter of record nor yet by deed or special instrument, but by mere oral evidence the most simple of any, or by notes unsenied, which are capable of a more easy proof, and therefore only better than a verbal promise.
2 Bl. Comm. 466.