Merriam-Webster Collegiate Dictionary - guarana

 noun  Etymology: Portuguese guarana, from Nhengatu (Tupi-based lingua franca of Amazonia), from Satere-Mawe (Tupian language of the middle Amazon River basin) warana  Date: 1838 a dried paste that is made from the seeds of a South American climbing shrub (Paullinia cupana) of the soapberry family, that contains caffeine and tannin, and that is used as a stimulant; also this plant