Definition of instantaneous in English:



  • 1Occurring or done in an instant or instantly.

    ‘her reaction was almost instantaneous’
    ‘modern methods of instantaneous communication’
    • ‘The Empires disappeared suddenly, as though in an instantaneous catastrophe.’
    • ‘Figure 2 demonstrates a rapid but not instantaneous decrease in elongation of primary roots of lupin when pressure was applied to entire axes.’
    • ‘The technology must be developed to make the transacting of money instantaneous.’
    • ‘It's that instantaneous direction change, the wheel-shredding asphalt grind that cooks up this sure winner on the attention-o-meter.’
    • ‘Being that he was from around these parts, his sense of direction was almost instantaneous.’
    • ‘Once airborne I could immediately feel the aircraft's sensitivity because every change in height and direction is instantaneous.’
    • ‘This is because the travel time of light, although very rapid, is not instantaneous.’
    • ‘The old USSR was run by men who did not see the abject and instantaneous murder of civilians as a reason to celebrate.’
    • ‘All of these, by virtue of the information age, are characterized today by rapid change and often instantaneous awareness.’
    • ‘Technology must be developed to make the transactions instantaneous.’
    • ‘With the instantaneous and free flow of information brought about by the Internet and other technological innovations what happens in, say, a remote part of Kalimantan or New York could reach Jakarta in a matter of minutes.’
    • ‘The instantaneous hostility of France to the second UN resolution proposed by Britain and America was presented last week as a brave moral stand by the French foreign minister, Dominique de Villepin.’
    • ‘What Barsamian's questions provoke is an eloquent and desperate plea for direct, instantaneous action.’
    • ‘This is an improvement over earlier systems that depended on the use of a stand-alone gas detector with alarm, which experts had to monitor continuously so that the reaction to any malfunction could be instantaneous.’
    • ‘This death would have been rapid, almost instantaneous.’
    • ‘Yet mathematicians were able to revolutionize the subject by inventing a whole new language of mathematics which was capable of expressing instantaneous change: that language was the calculus.’
    • ‘What was needed was a new, direct democracy with more instantaneous feedback to guide the political class.’
    • ‘Best practices at this point suggest rapid, but not instantaneous, installation of vendor packages.’
    • ‘Companies could efficiently share and distribute information, providing a faster decision-making process, effective internal communications and instantaneous feedback.’
    • ‘Inertia precludes limbs from making sharp directional changes or instantaneous starts and stops.’
    immediate, instant, on-the-spot, prompt, direct, swift, speedy, rapid, quick, expeditious, express, lightning
    sudden, hurried, hasty, precipitate, abrupt
    fleet, rathe
    View synonyms
  • 2Physics
    Existing or measured at a particular instant.

    ‘measurement of the instantaneous velocity’
    • ‘No object could acquire an instantaneous velocity of, let us say, 10 metres per second, at an instant of time t, while having zero velocity at all times surrounding t and thus failing to move any distance.’
    • ‘Mass, instantaneous velocity, acceleration, magnetic forces, and energy puzzled them much more.’
    • ‘Also in line with experimental measurements, the examination of instantaneous velocity of simulated beads shows that pause time decreases with increasing wall shear stress.’
    • ‘Owing to the intermittent nature of turbulence, we related individual predation events to local, instantaneous relative velocities instead of bulk averages.’
    • ‘The first instantaneous velocity equal to or greater than 10 mm/s defined the beginning of the movement.’


Mid 17th century: from medieval Latin instantaneus, from Latin instant- being at hand (from the verb instare), on the pattern of ecclesiastical Latin momentaneus.