adjective
-
occurring with almost no delay; immediate
-
happening or completed within a moment
instantaneous death
-
maths
-
occurring at or associated with a particular instant
-
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
-
Other Word Forms
Etymology
Origin of instantaneous
From the Medieval Latin word instantāneus, dating back to 1645–55. See instant, -an, -eous
Explanation
Something instantaneous is happening right now, without delay. In today's society, the technology we carry in our pockets means people often expect an instantaneous or immediate response to emails and text messages. Instantaneous comes from the Latin instant- meaning "being at hand." When something is instantaneous, it's right at hand when you need it. You can produce an instantaneous reply to someone or see an instantaneous change happen. If something happens very suddenly, you can describe it as instantaneous.
Vocabulary lists containing instantaneous
A Need for Speed: Synonyms for "Fast"
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
"Is Survival Selfish?" Vocabulary from the argument
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Auggie & Me
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The Amalfi also provides an instrument display for the passenger, configured to display vehicle data and telemetry, so lovers can whisper sweet nothings about instantaneous g-loading.
From The Wall Street Journal ● Sep. 26, 2026
A camera feeding a screen in front of the pilot relies on instantaneous computer processing to get round the lack of forward vision.
From BBC ● Sep. 24, 2026
Ryan and Myers said they were fascinated with how the American news media covered the kidnapping in instantaneous fashion and in an era long before the internet.
From Los Angeles Times ● Sep. 18, 2026
"The ballista spider's snare is bioengineered to store elastic energy in the silk and rapidly release it, giving it incredible instantaneous power density -- greater than any other specialized silk-based biological catapults," said Professor Narendra.
From Science Daily ● Jun. 26, 2026
Remarkably, the phenomenon was proved in 1997 when physicists at the University of Geneva sent photons seven miles in opposite directions and demonstrated that interfering with one provoked an instantaneous response in the other.
From "A Short History of Nearly Everything" by Bill Bryson
![]()
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.