testamentor

noun3

1. •
   One who makes a testament (any sense).

   • Just think—be the first testamentor to witness the great Nolan being tricked, defeated, or just plain ambushed. — 2022
2. •
   A testator.

   • In comparing decisions regarding last wills and testaments with each other, the sex of the testamentor or the locality are not essential, but the type of the testament might be. — 1986
3. •
   One who is named to be in charge of the inheritance named in a testament until it is discharged.

   • She gives to her son, John Callaghan, all the property that belonged to her at the time of her death. She appoints John Tasker, her son-in-law as her testamentor. — 2013