hickwall vs popinjay

hickwall

noun

  • A European green woodpecker, Picus viridis. 

  • A lesser spotted woodpecker, Dryobates minor. 

popinjay

noun

  • The green woodpecker, Picus viridis. 

  • A parrot. 

  • A target to shoot at, typically stuffed with feathers or plumage. 

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