compact disk vs forty-five

compact disk

noun
  • A form of digital media on a plastic disc read by a laser in a CD drive. It comes in several varieties including CD-ROM, CD-R, and CD-RW. 

forty-five

noun
  • A .45-caliber firearm. 

num
  • Cardinal number after forty-four and before forty-six. 

How often have the words compact disk and forty-five occurred in a corpus of books? (source: Google Ngram Viewer )