What is the meaning of Impromptu?

Improvised; without prior preparation, planning or rehearsal.

A short musical composition for an informal occasion often with the character of improvisation and usually to be played solo.

Any composition, musical or otherwise, that is created on the spot without preparation.

improvised, not planned

improvised action

impromptu

improvised, extemporaneous, unplanned: without prior preparation, planning, or rehearsal

impromptu

impromptu

impromptu

Source: wiktionary.org