split second
Barest flicker of time
A split second is an extremely brief moment—shorter than you can measure, barely long enough to register.
The phrase emphasizes instantaneous timing: In a split second, everything changed.
As a modifier, split-second describes decisions or reactions that happen almost without conscious thought: split-second timing, a split-second judgment call.
Passing very quickly
- momentaryLasting very briefly
- flashBrief burst of light
- blinkRapid lid movement
- heartbeatRhythmic cardiac contraction
jiffy · nanosecond · microsecond · tick · twinkling · wink · glimpse · short-lived
Happening without delay
- abruptSharp and unexpected
- suddenOccurring without prior notice
- spontaneousArising without external cause
- lightning-fastExtremely rapid
rapid · swift · snap · reflex · impulsive · unhesitating · quick-fire · hair-trigger
Involuntary stimulus response
- instinctInnate behavioral tendency
- reactionResponse to stimulus
- impulseSudden urge to act
- intuitionInstinctive immediate understanding
quick-thinking · life-or-death · critical · pivotal · crucial · make-or-break · do-or-die · clutch
Interval timing device
- chronometerPrecision timekeeping instrument
- countdownBackward enumeration to zero
- millisecondsThousandths of a second
- synchronizationAligning timing across systems
interval · clock · timer · lap · measure · precision · calibration · race
fleeting
Passing very quickly
heartbeat · jiffy · nanosecond · microsecond · tick · twinkling · wink · glimpse · short-lived · ephemeral
immediate
Happening without delay
- abruptSharp and unexpected
- suddenOccurring without prior notice
- spontaneousArising without external cause
lightning-fast · rapid · swift · snap · reflex · impulsive · unhesitating · quick-fire · hair-trigger · precipitous
reflex
Involuntary stimulus response
intuition · quick-thinking · life-or-death · critical · pivotal · crucial · make-or-break · do-or-die · clutch
stopwatch
Interval timing device
- chronometerPrecision timekeeping instrument
- countdownBackward enumeration to zero
- millisecondsThousandths of a second
synchronization · interval · clock · timer · lap · measure · precision · calibration · race
- time sayingstime flies, time is money, time heals all wounds, time will tell, carpe diem
- momentsmoment, second, flash, jiffy, tick
- Number Phrasesone and only, two cents, three strikes, four corners, five senses
- Quick wordsswift, rapid, fast, speedy, hasty
- Speed Expressionsin a flash, quick as a flash, in no time, like lightning, quick as lightning
- brief momentsjiffy, moment, second, flash, tick