occurring, done, or completed in an instant: an instantaneous response.
existing at or pertaining to a particular instant: the instantaneous position of the rocket.

Origin of instantaneous

From the Medieval Latin word instantāneus, dating back to 1645–55. See instant, -an, -eous
Related formsin·stan·ta·ne·i·ty [in-stan-tn-ee-i-tee, in-stuhn-tuh-nee-] /ɪnˌstæn tnˈi ɪ ti, ˌɪn stən təˈni-/, in·stan·ta·ne·ous·ness, nounin·stan·ta·ne·ous·ly, adverb

Synonyms for instantaneous Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for instantaneously

spontaneously, directly, immediately, pronto, quickly

Examples from the Web for instantaneously

Contemporary Examples of instantaneously

  • Instantaneously posting and garnering likes or retweets is the goal, as with increased notifications, the better the selfie.

    The Daily Beast logo
    The Selfie Olympics Are Upon Us

    Marina Watts

    January 8, 2014

  • The fact that doing so can instantaneously alleviate all our discomfort is hard to resist.

    The Daily Beast logo
    The Science of Breakups

    Amir Levine, Rachel Heller

    August 3, 2011

  • Which it goes ahead and does instantaneously, before you even get to the next page.

    The Daily Beast logo
    Twitter's Gangster Spam Trap

    Douglas Rushkoff

    September 30, 2009

Historical Examples of instantaneously

  • He sees at one glance and instantaneously all the past, present, and future.

  • Smoothly and instantaneously as a shadow Reddin eluded the attack.

    Earth's Enigmas

    Charles G. D. Roberts

  • I have never seen a stranger who won my regard so instantaneously.

    Ernest Linwood

    Caroline Lee Hentz

  • So instantaneously do they receive and understand God's revelations.

  • And instantaneously, as a baby at the breast, she found that all his strength and serenity were hers.


    E. F. Benson

British Dictionary definitions for instantaneously



occurring with almost no delay; immediate
happening or completed within a momentinstantaneous death
  1. occurring at or associated with a particular instant
  2. equal to the limit of the average value of a given variable as the time interval over which the variable is considered approaches zeroinstantaneous velocity
Derived Formsinstantaneously, adverbinstantaneousness or instantaneity (ɪnˌstæntəˈniːɪtɪ), noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for instantaneously



1640s (implied in instantaneously), formed in English from Medieval Latin *instantaneus, from instantem (see instant (n.)) on model of spontaneous. Related: Instantaneousness.

Online Etymology Dictionary, © 2010 Douglas Harper