chinquapin (chĭngˈkəpĭn) [key] [Algonquian], name for certain American species of the chestnut genus of the family Fagaceae (beech family) and for a related species, the golden chinquapin ( Castanopsis chrysophylla ), an evergreen of the Pacific states. The common chinquapin is Castanea pumila, native to the E United States. Its wood and fruit are used like those of the chestnut. The bush chinquapin ( C. alnifolia ) has a more southern range. Chinquapin is classified in the division Magnoliophyta, class Magnoliopsida, order Fagales, family Fagaceae.