Testamentary means related to a will. One appointed by will or testament may receive letters testamentary, authorizing them to distribute the assets. A testamentary trust is a trust created by the provisions in a will.
A person must have the mental competency to execute a will at the time the will was signed and witnessed. In a will contest, the issue of the decedent's lack of testamentary capacity is often argued. To have testamentary capacity, the author of the will must understand the nature of making a will, have a general idea of what he/she possesses, and know who are members of the immediate family or other "natural objects of his/her bounty." A person lacking testamentary capacity may be pressured into making a bequest by undue influence.
