Testator (noun)

1. A person who has made a will, especially one that is legally binding.
2. A person who makes a testimony, especially in a court of law.

Origin:

Late middle english: from latin, from testari 'to bear witness', from testis 'witness'. the original sense was 'a witness', later 'a person giving testimony'; the current sense dates from the mid 16th century.

Examples:

1. The testator left most of his estate to his only daughter.
2. The testator was called to the stand to give testimony about the accident.
3. The court had to determine if the testator was of sound mind when he wrote the will.
4. The testator was a wealthy man and his will created a great deal of controversy.
5. Before he died, the testator made sure to update his will to reflect his current wishes.