speed up

Formsspeeds up, speeding up, speeded up

1. 1
   go fasterphrasal verbidiomaticintransitive

   To go faster; to gain speed.

   The train sped up as it pulled away from the platform.

   Traffic tends to speed up after the last exit into town.

   Similaraccelerate, quicken

   Oppositeslow

   Note

   The intransitive use needs no object: the car sped up, traffic speeds up after the last exit. Up here does not point anywhere, which is why the opposite can be slow down or, just as well, slow up. For the past, both sped up and speeded up are correct.

2. 2
   go fasterphrasal verbtransitive

   To make something move or happen faster, increasing its speed.

   The city hopes the new rules will speed up the permit process for builders.

   The engineer sped up the conveyor belt to clear the backlog before the shift ended.

   Similaraccelerate, expedite, hasten, quicken

   Oppositeslow

   Note

   With an object, the particle can follow the verb or the object: speed up the process, speed the process up, but with a pronoun only speed it up. The passive is common for plans and services, and British railway writing of the 1960s uses speeded up there: the Moorgate service "has been most handsomely speeded up".

3. 3
   noun · speed-up

   Alternative spelling of speedup.

   Cutting two intermediate stops produced a noticeable speed-up on the express service.

   Running the job on eight processors gave roughly a sixfold speed-up.

   Note

   The hyphen is what turns the verb phrase into a noun: trains speed up, but a new timetable brings a speed-up. The plural is speed-ups, as in G. Freeman Allen's 1961 account of the new Leeds–Manchester service, where the speed-ups owe much to cutting intermediate stops. Written solid, speedup is the same word with the same range of meanings.

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