instantaneous

1 of 2

adjective

in·​stan·​ta·​neous ˌin(t)-stən-ˈtā-nē-əs 

-nyəs

1

: done, occurring, or acting without any perceptible duration of time

death was instantaneous

2

: done without any delay being purposely introduced

took instantaneous corrective action

3

: occurring or present at a particular instant

instantaneous velocity

instantaneity

ˌin-ˌstan-tə-ˈnē-ə-tē 

ˌin(t)-stən-tə-ˈnē-

noun

instantaneously

ˌin(t)-stən-ˈtā-nē-əs-lē 

-nyəs-lē

adverb

instantaneousness noun

instantaneity

2 of 2

noun

in·​stan·​ta·​ne·​i·​ty ˌinzˌtantᵊnˈēətē 

ənz-, 

-antəˈnē-, 

ˌinztəntəˈnē-, 

-n(ˌ)st-

plural -es

: the quality or state of being instantaneous

Synonyms of instantaneous

Adjective

• immediate
• instant

Examples of instantaneous in a Sentence

Adjective

We got an almost instantaneous response from the company.

the thunder following the flash of lightning was nearly instantaneous

Recent Examples on the Web

Adjective

With the craft's communications failing within the first two hours, the submersible imploded upon descent, resulting in their instantaneous deaths. —Dan Snierson, Entertainment Weekly, 16 June 2026

Speaking of which, when news broke Friday that much of the team’s equipment had been stolen, there was a nearly instantaneous social media ridiculing of the city. —Kansas City Star, 15 June 2026

Even with faster platforms, vaccine development is still not instantaneous. —Paul Adepoju, Scientific American, 14 June 2026

Seemed pretty instantaneous to me. —Scott Kramer, Forbes.com, 14 June 2026

Word History

Etymology

Adjective

borrowed from Medieval Latin instantāneus, from instant-, instans "moment, point of time," + Latin -āneus, suffix forming adjectives from temporal adverbs — more at instant entry 1

Note: Regarding the suffix -āneus see the etymology and note at spontaneous.

Noun

instantaneous + -ity

First Known Use

Adjective

1651, in the meaning defined at sense 1

Rhymes for instantaneous

• aeneas

Kids Definition

instantaneous

adjective

in·​stan·​ta·​neous ˌin(t)-stən-ˈtā-nē-əs 

-nyəs

1

: happening in an instant

2

: done without delay

instantaneously adverb

instantaneousness noun