impromptu

UK: /ɪmˈprɒmptjuː/

US: /ɪmˈprɑmptu, -tju/

US: (im promp′to̅o̅, -tyo̅o̅)

WordReference Random House Learner's Dictionary of American English © 2025

im•promp•tu /ɪmˈprɑmptu, -tyu/   adj. 

1. done without preparation:
   an impromptu party.

adv. 

2. without preparation:
   to deliver a speech impromptu.

WordReference Random House Unabridged Dictionary of American English © 2025

im•promp•tu  (im promp′to̅o̅, -tyo̅o̅), adj. 

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.

adv. 

4. without preparation:
   verses written impromptu.

n. 

5. something impromptu;
   an impromptu speech, musical composition, performance, etc.
6. Music and Dance a character piece for piano common in the 19th century and having, despite its title, a clear-cut form.

• Latin in promptū in readiness; see in, prompt
• French
• 1660–70

Synonyms

• 1. See extemporaneous. 

Collins Concise English Dictionary © HarperCollins Publishers::

impromptu / ɪmˈprɒmptjuː/ adjective

1. unrehearsed; spontaneous; extempore
2. produced or done without care or planning; improvised

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

Etymology: 17th Century: from French, from Latin in promptū in readiness, from promptus (adj) ready, prompt