Pactum de non alienando
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
A pact or agreement binding the owner of property not to alienate it, intended to protect the interests of another; particularly an agreement by the mortgagor of real estate that he wlil not transfer the title to a third person until after satisfaction of the mortgage.
See Mackeld.
Rom. Law, § 461,