pirozhki vs strudel

pirozhki

noun
  • A single such pastry. 

  • Small pastries filled with finely chopped meat, vegetables or fruit baked or fried, from eastern European cuisine, or a serving of these. 

strudel

noun
  • A pastry made from multiple thin layers of dough rolled up and filled with fruit, etc. 

  • Synonym of at sign (@) 

  • A vertical hole in sea ice through which downward jet-like, buoyancy-driven drainage of flood water is thought to occur. 

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