bracer

noun

1. That which braces, binds, or makes firm; a band or bandage.
2. Something bracing; a stimulant.

   “Country air in the fields, or in gardens, when breathed at proper hours, is an excellent bracer of the nerves, and a sure brightener of the complexion.”

   “In fact I did not feel good. I was suffering from the morning sickness of the steady, heavy drinker. What I needed was a pick-me-up, a bracer.”

3. A covering to protect the arm of the bowman from the vibration of the string.

   “To prevent the bow string from hanging on the left arm, it is covered with a piece of smooth leather, fastened on the outside of the arm, this is called a bracer.”

4. Armor for the forearm; a brassard.
5. A medicine, as an astringent or a tonic, which gives tension or tone to any part of the body.