What does "instantaneous" mean?

Occurring, arising, or functioning without any delay; happening within an imperceptibly brief period of time.

What is a synonym for "instantaneous"?

Common synonyms include: alert, apt, brief, compact, compendious, concise.

Pronounced //ɪnstənˈteɪni.əs//.

/ɪnstənˈteɪni.əs/ adj

adj ·Moderate ·College level

Adjective

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

"Lightning is nearly instantaneous."

From New Latin īnstāntāneus, from Latin īnstantem.