What is the term for fiduciary responsibility?

Fiduciary responsibility is a term concerning good stewardship of a portfolio, or a trust fund. In the case of many trust funds, a bank is the trustee of the Trust and by the will or contract made between the grantor and in this case a bank, the bank is obligated to exercise good review and proper care of the contents of the trust. Taxes are often part of the fiduciary responsibility.