el vs subway

el

noun
  • An elevated railway, especially for specific systems such as the metro in Chicago. 

  • The name of the Cyrillic script letter Л / л. 

  • The name of the Latin-script letter L. 

num
  • The cardinal number occurring after dek and before do in a duodecimal system. Written ↋, decimal value 11. 

article
  • the 

subway

noun
  • A rapid transit system, regardless of the elevation of its right of way; a metro system. 

  • An underground route for pipes, sewers, etc. 

  • An underground railway, especially for mass transit of people in urban areas. 

  • A train that runs on such an underground railway. 

  • An underground walkway, tunnel for pedestrians (called pedestrian underpass in US). 

verb
  • To travel by underground railway. 

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