What is a natural meat juice un- thickened and skimmed of fat?

You're describing meat broth, also sometimes called meat stock.

Here's the breakdown:

* Natural: This emphasizes that it's made from the natural juices of the meat, without any added flavorings or chemicals.

* Meat juice: This is the liquid that comes out of the meat during cooking.

* Un-thickened: This means it's not been reduced or thickened with any ingredients like flour or cornstarch.

* Skimmed of fat: The fat has been removed from the surface, leaving a clear, flavorful broth.

Meat broth is a versatile ingredient used in soups, sauces, stews, and many other dishes. It provides a rich, savory flavor and can be made from various types of meat.