split second

noun

1. a fraction of a second.

2. an infinitesimal amount of time; instant; twinkling.

split second

noun

1. an extremely small period of time; instant

adjective

1. made or arrived at in an infinitely short time

   a split-second decision

2. depending upon minute precision

   split-second timing

Other Word Forms

• split-second adjective

Word History and Origins

Origin of split second¹

First recorded in 1880–85

Idioms and Phrases

An instant, a fraction of a second, as in Our best swimmer came in a split second before theirs. This expression alludes to a stop watch that has two second hands, one above the other, for timing more than one athlete or intervals of a race by a single athlete. Each hand can be stopped independently of the other, so a second can be “split” when one second hand stops a fraction of a second after the other. [c. 1880]

Example Sentences

A split second after “Action!” was called, I darted across the hall to a better spot and ran through the frame.

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To be aware of, 'I'm on the ball here so this is what we trained' - but you have to think that in a split second.

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The lawyer who represented his family at his inquest, Gareth Naylor, tells the BBC that in a "split second" of an adult leaving the room, the toddler climbed on a bed and fell.

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What excites me is the maverick who gets you out of your seat and when possession-based football takes a rest for a split second and something magical happens.

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"I've never heard a sound like that in my life - it came from the sky. In a split second, the fighter jet flew over my head and crashed into the school building."

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Related Words

• blink of an eye www.thesaurus.com
• millisecond 
• nanosecond