Medical

You make a fist with your hand when you close your hand up tight and tuck all your fingers in together.
People often make fists when they are angry and want to punch someone.

A fleece is the entire coat of wool that is on an animal like a sheep. The term fleece is usually used to refer to the wool after it has been removed by shearing the sheep.

A flipper is an arm, leg or wing of an animal that lives in the sea. Flippers have been adapted for swimming and look very much like fish fins. Flippers can be seen on animals like whales, dolphins, seals and penguins.

Your forearm is the lower part of your arm, between your wrist and elbow.

The digitalis, or foxglove, is a very attractive garden plant that has flowers in various shades of pink. It is a biennial, native to western Europe and parts of Asia and Africa.
The entire plant is toxic, from roots to flowers. It is toxic fresh and dried, and if you have a vase of foxglove flowers, the water in the vase will be toxic too. A large enough dose will kill you, smaller doses cause hallucinations, nausea and severe headaches. It is toxic to people and animals, including cats and dogs.

Fur is the thick hair that covers many animals. If you are going to make a coat out of fur, it would be made from the skin of the animal as well as the fur that grows out of the skin.
Not to be confused with fir, a kind of tree.

Gills are what creatures that live in water use to breathe. Fish gills are easy to see, between their head and their side fins. Other creatures have less obvious gills, that look like fine, tufty growths.

A goatee is a kind of beard that is only on the point of a man's chin rather than on the sides of his face too. A goatee has that name because it looks a bit like the kind of beard goats have.

Your groin is the part of your body where your legs meet, also known as your crotch.

Gut is a slang word for your stomach and intestines or just that part of your body - the man in the picture has a large gut.
When you are preparing a whole animal to be cooked, the process of gutting it is the process of removing its internal organs, including its stomach and intestines.