doner kebab vs gyro

doner kebab

noun
  • A Turkish dish in which meat (typically seasoned lamb or mutton, but alternatively chicken or perhaps beef) is grilled on a revolving vertical spit; when cooked, the meat is sliced off and served with fresh vegetables in pita or rolled in a piece of unleavened flatbread. 

gyro

noun
  • A style of Greek sandwich commonly filled with grilled meat, tomato, onions, and tzatziki sauce. 

  • A gyrocompass. 

  • An autogyro. 

  • Synonym of detangler. 

  • A gyroscope. 

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