extempore

adj

1. Carried out with no preparation.
2. 1833 January, “Pandemonic Revels”, in The Royal Lady’s Magazine, and Archives of the Court of St. James’s, number XXV, London, page 15
3. 1833 January, “Pandemonic Revels”, in The Royal Lady’s Magazine, and Archives of the Court of St. James’s, number XXV, London, page 15: Sheets, tablecloths, white gowns, and pocket-handkerchiefs were instantly in demand, and every one, as has been seen, entered, con amore, into the extempore entertainment of Pandemonic Revels.

adv

1. Without preparation; extemporaneously.

noun

1. Something improvised.