IPA: //ˈtɛstətər//
KK: /ˈtɛstətər/
A person who creates a will to specify how their property and affairs should be handled after they die.
The testator clearly outlined their wishes in the will.
Testator → It is formed from "testari" (meaning to witness or testify) and the suffix "-tor" (meaning one who). A testator is one who witnesses or testifies to a will, specifically the person who makes a will.
Think of someone who 'testifies' ('testari') about their wishes for after they are gone — that's why a testator is the person who makes a will.