Testamentary capacity is a legal term that refers to an individual's ability to understand the consequences of their actions when creating or executing a last will and testament. Some synonyms for testamentary capacity include mental capacity, legal capacity, sound mind, and capacity to execute a will. These terms reflect the requirement that a testator must be of sound mind and understand the nature of their property and the individuals they are bequeathing it to in order to create a legally binding will. Other related terms include competency, testamentary competency, and understanding, all of which relate to a person's mental ability to create a legally valid will.