instantly

American  

[in-stuhnt-lee] / ˈɪn stənt li /

adverb

1. immediately; at once.

   Synonyms:

   forthwith

2. urgently.

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conjunction

1. as soon as; directly.

   I recognized her instantly she entered the room.

instantly British  

/ ˈɪnstəntlɪ /

adverb

1. immediately; at once

2. archaic urgently or insistently

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Related Words

See immediately.

Etymology

Origin of instantly

Late Middle English word dating back to 1375–1425; see origin at instant, -ly

Explanation

Something happens instantly when there's no pause or delay at all before it occurs. If you fall asleep as soon as your head touches your pillow, you can say you drifted off instantly. If an event is immediate, it happens instantly. Your parents might say they fell in love instantly, the moment they first saw each other, and you may realize instantly on the first day of school that you are going to love your history class. The adverb instantly first meant "persistently," rather than "immediately," though it soon gained this meaning. The Medieval Latin root is instantem, "pressing, urgent," or "standing near."

Example Sentences

Even so, researchers have struggled to fully understand how these molecules form because many of the key intermediate stages are highly unstable and disappear almost instantly.

From Science Daily • May 22, 2026

And sometimes — the true jackpot — there’s a crusty half-loaf of sourdough, which instantly checks off one of my weekly anchor ingredients for just a few dollars.

From Salon • May 22, 2026

This one offered up Wednesday remains instantly recognizable, though.

From The Wall Street Journal • May 21, 2026

"I said instantly: 'No, I'll do it now. I don't need any time to think about it. I'm 100% ready to do it.'"

From BBC • May 19, 2026

All eyes instantly land on us, and there are dozens of them.

From "The Manifestor Prophecy" by Angie Thomas

Related Words

• directly
• immediately
• instantaneously
• right away