testator

Etymology

From Latin testator (“one who makes a will, in Late Latin also one who bears witness”), from testari (“to bear witness, make a will”). See testament.

noun

1. (law) One who makes or has made a legally valid will.
   […] there is an exception “in the cases of heir and executor, who may plead a release to the ancestor or testator whom they respectively represent; so also with respect to several tortfeasors, for in all these cases there is a privity between the parties which constitutes an identity of person”. 1881, Oliver Wendell Holmes, The Common Law