As used in this chapter, unless the context requires otherwise, "will": (1) Means a last will or testament, codicil, appointment by will, writing in the nature of a will in exercise of a power, and any other testamentary disposition; and (2) Includes a codicil and any testamentary instrument that merely appoints an executor, revokes or revises another will, nominates a guardian, or expressly excludes or limits the right of an individual or class to succeed to property of the decedent passing by intestate succession.