instantaneous

American  

[in-stuhn-tey-nee-uhs] / ˌɪn stənˈteɪ ni əs /

adjective

1. occurring, done, or completed in an instant.

   an instantaneous response.

   Synonyms:

   abrupt, sudden, immediate

2. existing at or pertaining to a particular instant.

   the instantaneous position of the rocket.

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instantaneous British  

/ ˌɪnstənˈteɪnɪəs, ɪnˌstæntəˈniːɪtɪ /

adjective

1. occurring with almost no delay; immediate

2. happening or completed within a moment

   instantaneous death

3. maths

   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 zero

      instantaneous velocity

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Other Word Forms

• instantaneity noun
• instantaneously adverb
• instantaneousness noun

Etymology

Origin of instantaneous

From the Medieval Latin word instantāneus, dating back to 1645–55. See instant, -an, -eous

Example Sentences

That would have taken me a whole day five years ago; now it’s instantaneous and free to everybody.

From The Wall Street Journal

But it also conveys facts, often supported by real-time video, and instantaneous access to underlying truth.

From The Wall Street Journal

The instantaneous send-off that electric cars have made it an amusement park at every stop light.

From The Wall Street Journal

Part of the problem is that because we have all these instantaneous connections, people feel like they can make more last-minute changes.

From Los Angeles Times

Despite instantaneous, zero-fee transactions, the explosion of exchange-traded funds, and algorithmic trading, the economic role of the U.S. public markets has been in quiet retreat.

From Barron's

Related Words

• rapid
• spontaneous
• transitory