Vadium vivum

from The Collaborative International Dictionary of English v.0.48

Vadium \Va"di*um\, n. [LL., from L. vas, vadis, bail.] (Law)
   Pledge; security; bail. See {Mortgage}.
   [1913 Webster]

   {Vadium vivum} [LL.] (Law), a living pledge, which exists
      where an estate is granted until a debt is paid out of its
      proceeds.
      [1913 Webster]

from Bouvier's Law Dictionary, Revised 6th Ed (1856)

VADIUM VIVUM, contracts. A species of security by which the borrower of a 
sum of money, made over his estate to the lender, until he had received that 
sum out of the issues and profits of the land; it was so called because 
neither the money nor the lands were lost, and were not left in lead pledge, 
but this was a living pledge, for the profits of the land were constantly 
paying off the debt. Litt. sect. 206; 1 Pow. on Mort. 3; Termes de la Ley, 
h.t.