Real Dictionary

blueberry
countable noun: A blueberry is a small dark blue fruit that is found in North America. Blueberries are usually cooked before they are eaten.

blueberry in American English
any of a genus (Vaccinium) of shrubs of the heath family, bearing small, edible, blue-black berries with tiny seeds and a whitish, waxy bloom
noun: the edible, usually bluish berry of various shrubs belonging to the genus Vaccinium, of the heath family

blueberry in British English
noun: any of several North American ericaceous shrubs of the genus Vaccinium, such as V. pennsylvanicum, that have blue-black edible berries with tiny seeds