discretionary trust

from WordNet (r) 3.0 (2006)

discretionary trust
    n 1: a trust that gives the trustee discretion to pay the
         beneficiary as much of the trust income as the trustee
         believes appropriate

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

DISCRETIONARY TRUSTS. Those which cannot be duly administered without the 
application of a certain degree of prudence and judgment; as when a fund is 
given to trustees to be distributed in certain charities to be selected by 
the trustees.