quadruple

Etymology

From Middle English quadruple, from Latin quadruplus. Can be analyzed as quadri- + -ple.

adj

1. Being four times as long, as big or as many of something.
   He's quite an athlete and can do quadruple jumps with ease.

verb

1. (transitive) To multiply by four.
   Quadrupling four gives sixteen.
2. (intransitive) To increase by a factor of four.
   Our profits quadrupled when we made the improvements.
3. (rail transport) To provide four parallel running lines on a given stretch of railway.
   Quadrupling the short remaining stretch of three-track railway north of Rugby, left over by the turn of the century modernisation, is a possibility that could be pursued. 2019 October, “Railtalk: HS2 delay - time for lateral thinking”, in Modern Railways, page 7
   A long-term aspiration is to quadruple the cross-country route between Peterborough and Werrington Junction, removing any conflict between trains on the Spalding and Leicester lines. April 22 2020, Paul Shannon, “Felixstowe: Is 47 trains a day achievable?”, in Rail, page 52

noun

1. Something that is four times the usual number, amount, size, etc.
2. (skating) A figure-skating jump with four revolutions in the air.