acerola
noun
ac·er·o·la ˌa-sə-ˈrō-lə 
: any of several tropical American shrubs (genus Malpighia of the family Malpighiaceae)
especially : a large shrub or small tree (Malpighia glabra synonym M. punicifolia) found from Texas to northern South America and the West Indies that has mildly acid cherrylike fruits very rich in vitamin C
Example Sentences
Recent Examples on the Web Retinol has long been promoted as a beauty enhancer, and their black cherry, acerola and pomegranate concoction is the first drinkable version, the company says. 
Michele Corriston, PEOPLE.com, 8 July 2019
Michele Corriston, PEOPLE.com, 8 July 2019 Word History
Etymology
borrowed from American Spanish, going back to Spanish, "fruit of the hawthorn Crataegus azarolus," earlier (14th-century Aragon) azarolla, borrowed from Arabic az-zaʽrūra, from az (assimilated form of al "the") + zaʽrūra, zuʽrūra, derivative of zuʽrūr "the hawthorn Crataegus azarolus"
First Known Use
1875, in the meaning defined above
Medical Definition
acerola
noun
ac·er·o·la ˌas-ə-ˈrō-lə
: a West Indian shrub (genus Malpighia) with mildly acid cherrylike fruits rich in vitamin C