Longman Dictionary of Contemporary English
Wiktionary
n. 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.
WordNet
n. carbonated drink containing extracts of roots and herbs
Wikipedia
Root beer is a tan sweet beverage traditionally made using the root beer tree Sassafras albidum (sassafras) or the vine Smilax ornata (sarsaparilla) as the primary flavor. Root beer may be alcoholic or non-alcoholic, come naturally decaffeinated or have caffeine added, and may be carbonated or non-carbonated. Most root beer has a thick foamy head when poured. Modern, commercially produced root beer is generally sweet, foamy, carbonated, and non-alcoholic, and is flavoured using sassafras.
Usage examples of "root beer".
Max returned to Rodale & Burns, pouring his energies into a new advertising campaign for Old Faithful Root Beer.
Ukiah finished the second chili dog and the last of the root beer.
Bobby Hollingsworth and I made up another batch of punch by pouring grape juice, sparkling water, and root beer into a cut-glass bowl.
Every Thursday night Aunt Cindy came into town to do her shopping at Crossen's store and she'd send me in here to have a root beer.
Then he shook the can of root beer as hard as he could, pointed it at her, and popped the top.
Delmonico even rounded me up a bottle of root beer (though I think he had to send one of his boys out to fetch it from a local grocer).
The hypercarbonated soda served on the plane to Miami put him in mind of Old Faithful Root Beer.
Black was on the next chair, three empty root beer cans next to his foot.
It smelled like root beer, and tasted much like that, but it was hot and it warmed him.
It smelled like root beer, add tasted much like that, but it was hot and it warmed him.
The water was naturally carbonated, and they made Wyler's root beer in their canteens.
The pizza arrived shortly after he got out of the bath, and Shadow ate it, washing it down with a can of root beer.
For each of them, Agnes put one scoop of vanilla ice cream in a tall glass of root beer, and after changing quickly into their pajamas, they sat together in Barty's bed, enjoying their treats, while she read aloud the last sixty pages of Starman Jones.