Black's Law Dictionary (2nd edition)dictionaries

Blanc Seign

In Louisiana, a paper signed at the bottom by him who intends to bind hlmself, give acquittance, or compromise, at the discretion of the person whom he intrusts with such blanc seign, giving him power to fill it with what he may think proper, according to agreement Musson v. U. S. Bank, 6 Mart O. S. (La.) 718

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