Testamentary Will

The term "testamentary will" just represents a fancy way to describe a normal will. Like, the kind of will you think of when you think of a will. That is, a document outlining which relatives get which things after someone dies.

If you're a lawyer, or just someone who insists on using the long name for something (the kind of person who routinely says words like "tarpaulin" or "television"), you would call these documents "testamentary wills."