English Reference
Adjective

instantaneous

adj.
C1 Advanced US /ˌɪnstənˈtæniəs/ UK /ˌɪnstɑːntˈeɪniəs/ in·stan·ta·neous

adj.happening or done immediately, without any delay. You use this to describe something that occurs in a split second.

adj.occurring or completed in an instant; characterized by immediate action or effect. Often used in technical or scientific contexts to describe processes with no perceptible duration.


SIMPLE

The new messaging app provides instantaneous communication.

CONTEXTUAL

The driver's reaction to the obstacle was instantaneous, preventing what could have been a serious accident.

COMPLEX

In the digital age, we have become accustomed to the almost instantaneous retrieval of information, which has fundamentally altered our expectations of service and response times.

Usage

Typically used as an attributive adjective before a noun; often non-gradable in technical contexts.

Pitfall
an instantaneous of reactionan instantaneous reaction

Learners sometimes confuse the adjective 'instantaneous' with the noun 'instant' and try to use it with a prepositional phrase.

Despite the internet’s capacity for instantaneous interaction, followers have proved a poor replacement for friends.

The Conversation· 19 Aug 2026

I suspect relatively soon offsides will be almost fully automated, which probably makes sense so long as it’s almost instantaneous.

The Guardian· 10 Aug 2026

From New Latin īnstāntāneus, from Latin īnstantem.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin instans
Level C1 · Advanced
Frequency Occasional
Updated