bilberry vs teaberry

bilberry

noun
  • Vaccinium myrtillus, the wild European blueberry of the cowberry family. 

  • The shrub of the above-mentioned plant. 

teaberry

noun
  • A berry which is the fruit of a small shrub native to northeastern North America, Gaultheria procumbens (eastern teaberry, American wintergreen, boxberry, checkerberry). 

  • A pinkish-white edible berry which grows in the Falkland Islands, where the fruits are harvested annually by Islanders to make cakes, confectionary and pavlovas. On the South American mainland the leaves are brewed for tea (Myrteola nummularia). 

How often have the words bilberry and teaberry occurred in a corpus of books? (source: Google Ngram Viewer )