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

These decisions need to be made in split seconds around the rim, and the cat-and-mouse game that big defenders have to play against guards is exceedingly difficult. —Sam Vecenie, The Athletic, 14 Jan. 2025

Vegas scored for the second time in four games a split second after the horn sounded to end a period, and the Rangers-Knights game remained tied 1-1 into the 3rd period. —Jay Ginsbach, Forbes, 12 Jan. 2025

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