adj ·Uncommon ·College level

Definitions

Adjective

1. 1
   Occurring, arising, or functioning without any delay; happening within an imperceptibly brief period of time. not-comparable

   "This instantaneous motion is supposed by you, to be infinitely swift."

Adjective

1. 1
   occurring with no delay wordnet

Synonyms

All synonyms

fastinstantimmediateinstantalertapt

Antonyms

All antonyms

delayedgradualnonimmediatenoninstantaneous

Example

More examples

"Lightning is nearly instantaneous."

Etymology

From New Latin īnstāntāneus, from Latin īnstantem.

Related phrases

instantaneous velocitysuper-instantaneous

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.