carambola, orange fleshy fruit of Averrhoa carambola, a small shrub in the wood sorrel family (Oxalidaceae). The fruits have five very prominent ridges, and in transverse section appear as a five-pointed star and thus are often called star fruit. The fruits contain high levels of oxalic acid which makes them sour to the taste. Cultivated varieties have been selected to be sweeter when eaten raw. The juice is often used to remove stains from clothing and other articles, because of the oxalic acid. Carambola is classified in the division Magnoliophyta, class Magnoliopsida, order Geraniales, family Oxalidaceae.