R vs X

R

character
  • The eighteenth letter of the English alphabet, called ar and written in the Latin script. 

name
  • In the context of the documentary hypothesis, the Redactor(s) who compiled and edited the Torah. 

adj
  • right (as opposed to left) 

  • reverse 

  • restricted 

noun
  • rex (“king”) or regina (“queen”); the initial by which a British monarch signs documents after his or her name 

  • the Crown, the government of a monarchy (abbreviating rex (“king”) or regina (“queen”)) 

  • rook 

  • Thursday 

  • Republican 

  • ring 

  • runs, the statistic reporting the number of runs scored by a player 

  • radius 

X

character
  • The twenty-fourth letter of the English alphabet, called ex and written in the Latin script. 

name
  • A surname, used by those who have had their identity or heritage, including their proper ancestral names, erased or forgotten. 

  • Christ 

  • A placeholder for an unknown, suppressed or hypothetical name. 

num
  • An unknown quantity or unknown value. 

noun
  • Any mark that looks like that letter, such as a mark made by a person who cannot read or write in lieu of a signature. 

  • Cross, crossing. 

  • The spot behind the goal. 

  • Ecstasy, a particular street drug. 

adj
  • Obscene. 

  • Intersex or non-binary (in passports and identification documents). 

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