4 vs quadruplet

4

quadruplet

noun
  • One of a group of four, particularly one of four babies born from the same mother during the same birth. 

  • A tuplet of four notes. 

  • A sequence of four elements. 

  • A cycle for carrying four riders, arranged so that all the riders can assist in the propulsion. 

How often have the words 4 and quadruplet occurred in a corpus of books? (source: Google Ngram Viewer )