: a very short period of time
In a split second, it was all over.
always used before a noun
1
: done very quickly
a split-second decision
2
: very accurate or precise
split-second timing
Cite this Entry
“Split second.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/split%20second. Accessed 23 Jun. 2026.
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