impromptu

American  

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

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

impromptus plural

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

Synonym Usage

See extemporaneous.

Other Word Forms

Noun Inflected Forms

• impromptus
  plural

Etymology

Origin of impromptu

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

Explanation

Some of the best kinds of parties are impromptu ones, when you decide at the last minute to get together. The adjective impromptu describes things done or said without previous thought or preparation. Impromptu is also used as an adverb: Most people are not able to speak impromptu in front of an audience. This word was borrowed from French and ultimately derives from the Latin in prōmptū ("at hand, in readiness") from in ("in") plus a form of prōmptus ("readiness"). As you can guess from the spelling, the adjective and verb prompt are related to impromptu; they are from the same Latin verb, prōmere, "to bring forth."

Example Sentences

Anderson, who had briefly worked as an actress in Hollywood, was a stunning blond socialite, clad in a black cocktail dress, with a penchant for impromptu dance.

From The Wall Street Journal • Jul. 8, 2026

That prompted Justice Samuel Alito, who wrote the majority opinion, to issue an impromptu retort, saying he hadn’t known that Sotomayor was going to do that.

From The Wall Street Journal • Jun. 28, 2026

Videos posted to social media showed crowds chanting, singing and cheering in the streets, while impromptu block parties stretched across avenues in parts of the city.

From Salon • Jun. 14, 2026

On game nights, throngs of supporters donning Knicks gear have been spilling out of packed bars, projecting the game onto the sides of buildings, and holding impromptu watch parties.

From BBC • Jun. 8, 2026

The larger houses had become impromptu apartment buildings, their porches converted into additional rooms.

From "A Confederacy of Dunces" by John Kennedy Toole

Related Words

• offhand
• spontaneous
• unscripted