d vs p

d

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

symbol
  • a British penny; an old penny (the modern decimal penny being abbreviated p). 

  • Die or dice 

  • penny, a measure of the size of nails 

prefix
  • the prefix dis- or des- 

p

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

noun
  • proton 

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