split-second

1 of 2

adjective

split-sec·​ond ˈsplit-ˈse-kənd 

1

: occurring in a split second

a split-second decision

2

: extremely precise

split-second timing

split second

2 of 2

noun

: a fractional part of a second : flash

Synonyms

Adjective

• immediate
• instant
• instantaneous
• straightaway

Noun

• beat
• eyeblink
• flash
• heartbeat
• instant
• jiff
• jiffy
• minute
• moment
• nanosecond
• New York minute
• second
• shake
• trice
• twinkle
• twinkling
• wink

Examples of split-second in a Sentence

Adjective

a day trader who is used to making split-second decisions

Noun

In a split second, it was all over.

a devastating accident can cause everything in your life to change in a split second

Recent Examples on the Web

Adjective

While now reflects on the the split-second decision to jump into action, switching to a hero-protector mode. —Nellie Andreeva, Deadline, 10 Jan. 2025

After Barkley leaped over a Jaguars defender backward, a reporter asked Barkley how that even registered as a split-second option in his mind. —Brooks Kubena, The Athletic, 9 Jan. 2025

Noun

Over the past few years, it’s been mostly impossible to see Bob Dylan perform anywhere in America besides dark, hushed theaters where ushers dive on anyone that dares to take to a phone for even a split second. —Andy Greene, Rolling Stone, 25 Dec. 2024

The focus is fast enough to snap from close to distant subjects in a split second in most instances. —PCMAG, 11 Dec. 2024

Word History

First Known Use

Adjective

1944, in the meaning defined at sense 1

Noun

1912, in the meaning defined above

Kids Definition

split second

1 of 2 noun

: a small fraction of a second : flash

split-second

2 of 2 adjective

1

: occurring in a split second

a split-second decision

2

: extremely precise

split-second timing