What is the meaning of Root_beer?

A beverage, most often a carbonated soft drink made from a combination of vanilla, cherry tree bark, licorice root, sarsaparilla root, sassafras root bark, nutmeg, anise, and molasses, among other things.

A dark reddish-brown color, like the drink.

root beer (beverage made with sarsaparilla root)

Source: wiktionary.org