impromptu speech

Translations
неподготовленная речь
He gave an impromptu speech at the meeting.
Он произнёс неподготовленную речь на собрании.
Definitions
An impromptu speech is a type of speech that is delivered without prior preparation or rehearsal, often in response to a prompt or unexpected situation, requiring the speaker to think quickly and articulate their thoughts on the spot.
Words
speech

noun
речь
impromptu

adjective
импровизированный