em vs quadruple

em

noun
  • A unit of measurement equal to the height of the type in use. 

  • The name of the Cyrillic script letter М / м. 

  • The name of the Latin-script letter M. 

intj
  • a form of hesitant speech, or an expression of uncertainty; um; umm; erm 

pron
  • A gender-neutral third-person singular object pronoun, the objective case of ey, equivalent to the singular them and coordinate with him and her. 

quadruple

noun
  • Something that is four times the usual number, amount, size, etc. 

  • A figure-skating jump with four revolutions in the air. 

verb
  • To multiply by four. 

  • To increase by a factor of four. 

  • To provide four parallel running lines on a given stretch of railway. 

adj
  • Being four times as long, as big or as many of something. 

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