Synonyms of instantaneous

instantaneous

adjective

ˌin(t)-stən-ˈtā-nē-əs 

as in immediate

done or occurring without any noticeable lapse in time

the thunder following the flash of lightning was nearly instantaneous

Synonyms & Similar Words

• immediate
• instant
• rapid
• split-second
• swift
• summary
• straightaway
• quick
• speedy
• prompt
• fast
• hit-and-run

Antonyms & Near Antonyms

• slow
• prolonged
• sluggish
• protracted
• tardy
• dilatory
• deferred
• delayed

Example Sentences

Recent Examples of instantaneous

But fantasy sports, an almost quaint precursor to the instantaneous forms of gambling proliferating now, remains hugely prevalent. — Hannah Keyser, CNN Money, 3 Sep. 2026

But his son went to meet Kaya, and the connection was almost instantaneous. — Alicia Urrea, Billboard, 27 Aug. 2026

And all have been just as vulnerable to the near-instantaneous bootlegging. — Gene Maddaus, Variety, 21 Aug. 2026

In his Missouri Western dormitory office on Wednesday morning, Reid acknowledged an instantaneous turn toward 2026. — Kansas City Star, 19 Aug. 2026