whortleberry a name loosely applied, in ways which vary from country to country, to various sorts of berry. All or almost all are of the genus Vaccinium to which the blueberry belongs. The name is best reserved for V. myrtillus (bilberry), but allowable also for what is often called bog bilberry, V. uliginosum. These berries are relatively large and blue-black in colour, but less good to eat than the blueberry.
In Ireland whortleberries are also called fraughans and for the activities that surrounded Fraughan Sunday and similar celebrations in England, see the entry for bilberry. The name ‘red whortleberry’, when met, probably refers to cranberry/lingonberry.