1. “Beneficiary” means and includes any person entitled, but for his disclaimer, to take an interest, by intestate succession; by devise; by legacy or bequest; by succession to a disclaimed interest by will, intestate succession or through the exercise or nonexercise of a testamentary power of appointment; by virtue of a renunciation and election to take against a will; as beneficiary of a testamentary trust; pursuant to the exercise or nonexercise of a testamentary power of appointment; as donee of a power of appointment created by testamentary instrument; or otherwise under a testamentary instrument;

2. “Interest” means and includes the whole of any property, real or personal, legal or equitable, or any fractional part, share or particular portion or specific assets thereof or any estate in any such property or power to appoint, consume, apply or expend property or any other right, power, privilege or immunity relating thereto; and

3. “Disclaimer” means a written instrument which declines, refuses, releases, renounces or disclaims an interest which would otherwise be succeeded to by a beneficiary, which instrument defines the nature and extent of the interest disclaimed thereby and which must be signed, witnessed and acknowledged by the disclaimant in the manner provided for deeds of real estate.