Definition of before you can say knife in US English:

phrase

• Very quickly; almost instantaneously.

  Example sentences

  • ‘The days rolled by in the camp - they were over before you could say knife.’

  Synonyms

  soon, very soon, in a second, in a minute, in a moment, in a trice, in a flash, shortly, any second, any minute, any minute now, in a short time, in an instant, in less than no time, in no time at all, in next to no time, before you know it, before long

  View synonyms