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

• instantaneous
• immediate
• instant

Noun

• minute
• second
• moment
• heartbeat

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

Miami further stresses defenses by often putting them in motion at the snap to force split-second communication in opposing secondaries. —Andrew Callahan, Boston Herald, 13 Sep. 2025

In-game betting is so popular and such a draw that gamblers are making split-second decisions based on the stats displayed. —Contessa Brewer,alex Sherman, CNBC, 11 Sep. 2025

Noun

The split second the clock turns to the opening hour, buoys from every ship are tossed in the water and the 250-fathom deep gill net is cranked out by the deckhands. —Andrew Watman, Forbes.com, 11 Sep. 2025

Garfield blinked in shock a few times before rocketing out of his chair for a split second, then spinning around to uncomfortably look at his co-stars. —Bethy Squires, Vulture, 8 Sep. 2025

Word History

First Known Use

Adjective

1944, in the meaning defined at sense 1

Noun

1912, in the meaning defined above

Rhymes for split-second

• beckoned
• reckoned
• second
• seconde
• femtosecond
• microsecond
• millisecond
• nanosecond
• picosecond

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