impromptu

American  

[im-promp-too, -tyoo] / ɪmˈprɒmp tu, -tyu /

adjective

1. made or done without previous preparation.

   an impromptu address to the unexpected crowds.

2. suddenly or hastily prepared, made, etc..

   an impromptu dinner.

3. improvised; having the character of an improvisation.

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adverb

1. without preparation.

   verses written impromptu.

noun

1. something impromptu; an impromptu speech, musical composition, performance, etc.

2. a character piece for piano common in the 19th century and having, despite its title, a clear-cut form.

impromptu British  

/ ɪmˈprɒmptjuː /

adjective

1. unrehearsed; spontaneous; extempore

2. produced or done without care or planning; improvised

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adverb

1. in a spontaneous or improvised way

   he spoke impromptu

noun

1. something that is impromptu

2. a short piece of instrumental music, sometimes improvisatory in character

Related Words

See extemporaneous.

Etymology

Origin of impromptu

First recorded in 1660–70; from French, from Latin in promptū “in readiness”; in, prompt

Example Sentences

Little stone circles had been laid as impromptu memorials to the men at the site where they died, a little Palestinian flag flapping above one.

From Barron's • Mar. 15, 2026

One protester climbed onto an impromptu stage and bravely proclaimed: "I am a Yoon voter... But he really crossed the line. I regret voting for him."

From BBC • Feb. 22, 2026

Stella’s restless energy in wanting to fix things spurs her to arrange an impromptu trip for them to Amsterdam.

From Los Angeles Times • Feb. 20, 2026

I love an impromptu party, especially in the dead of winter and when it involves a luxurious, steamy bowl of soup.

From The Wall Street Journal • Feb. 19, 2026

Outside Goetz’s apartment building, on the evening of the verdict, there was a raucous, impromptu street party.

From "The Tipping Point" by Malcolm Gladwell

Related Words

• offhand
• spontaneous
• unscripted