grapefruit vs pomelo

grapefruit

noun
  • The large spherical tart fruit produced by this tree. 

  • The tree of the species Citrus paradisi, a hybrid of pomelo (Citrus maxima) and sweet orange. 

pomelo

noun
  • The tree which produces this fruit. 

  • the grapefruit. 

  • The large fruit of the Citrus maxima (syn. C. grandis), native to South Asia and Southeast Asia, with a thick green or yellow rind, a thick white pith, and semi-sweet translucent pale flesh. 

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