English numbers (edit)
[a], [b] ←  3 4 5  → 
    Cardinal: four
    Ordinal: fourth
    Multiplier: quadruple
    Distributive: quadruply
    Fractional: quarter, fourth
    Number of musicians: quartet

Pronunciation change

Adjective change

Positive
quadruple

Comparative
none

Superlative
none

  1. If something is quadruple, it is 300% bigger than something else.
    He's quite an athlete and can do quadruple jumps with ease.

Verb change

Plain form
quadruple

Third-person singular
quadruples

Past tense
quadrupled

Past participle
quadrupled

Present participle
quadrupling

  1. (transitive) If you quadruple something, you multiply it by four.
    Quadrupling four gives sixteen.
  2. (intransitive) If something quadruples, it increases by a factor of four.
    Our profits quadrupled when we made the improvements.