As used in this chapter, unless the context otherwise requires:
(1) “Governing instrument” means: A will, deed, trust instrument or agency agreement;
(2) For purposes of subdivision (1)(A), an agency agreement includes but is not limited to, any agreement under which any delegation is made, either pursuant to § 35-15-807 or by anyone holding a power or duty pursuant to chapter 15, part 12;
(3) “Trust” means any fiduciary relationship created by a governing instrument; and
(4) “Trustee” means any fiduciary as defined in § 35-15-103.