trust fund

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A collection of property, especially money and securities, held by one party, such as a parent, for the benefit of another, such as a child.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun law Property held by a trustee in a trust established by a grantor for a beneficiary.
• noun Loosely, a substantial inheritance of money.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a fund held in trust