DictionaryextemporeWithout preparation
adverb / adjective

extempore

ik-STEM-puh-ree/ɪkˈstempəri/

Done or performed without preparation or rehearsal.

The performer acts extempore, inventing an astronaut routine with an unexpected prop.

A compact two-panel sequence shows a performer blindly drawing an unexpected household prop, then immediately inventing a theatrical astronaut act with it: performing extempore, without preparation or rehearsal.
Etymology

Literally “out of time,” the Latin phrase meant “offhand” or “according to the needs of the moment.” It describes responding as the occasion arises rather than preparing or rehearsing beforehand.

In context

BeerBiceps63:03
he says that almost extemporaneously, he broke into tears and he composed this poem extempore and started singing it in his own way.
Dr. Vikram Sampath - EXPOSING FALSE Indian History - Gandhi, Godse & Nehru | The Ranveer Show 273

More examples

  • His extempore speech includes a few jokes about the occasion.
  • The pianist plays extempore while the guests find their seats.
  • Without consulting her notes, the professor answers extempore.

Forms

extemporize verb — Speak or perform without advance preparation.

Similar words

impromptu
Emphasizes something arranged or done on the spot.
unrehearsed
Specifically emphasizes that a performance has not been practiced.
spontaneous
Emphasizes a natural impulse rather than deliberate preparation.