quadruple

Adjective

• four times as great or many
  • a fourfold increase in the dosage
    

• having four units or components
  • quadruple rhythm has four beats per measure
    
  • quadruplex wire
    

Noun

• a quantity that is four times as great as another

• a set of four similar things considered as a unit

Verb

• increase fourfold
  • His stock earning quadrupled
    

Related words

• Synonyms: 
  fourfold , four-fold , quadruplicate , quadruplex , quartet , quartette , quadruplet