extemporize

Etymology

verb

1. (intransitive) To perform or speak without prior planning or thought; to act in an impromptu manner; to improvise.
   "Will you please tell me whose music you have been playing?" . . . "It's nobody's, miss." "Do you mean you have been extemporizing all this time?" 1881, George MacDonald, chapter 35, in Mary Marston
   But while some of his predecessors liked to extemporize, Obama prefers the message to be just so. March 5 2009, Peter Baker, “The (very) scripted president”, in New York Times, retrieved 2011-11-08
2. (transitive) To adapt, improvise, or devise action or speech in an impromptu or spontaneous manner.
   As the music came fresher on their ears, they danced to its cadence, extemporizing new steps and attitudes. 1860, Nathaniel Hawthorne, chapter 10, in The Marble Faun
   The small jelly-speck, which we call the amoeba, has no organs save what it can extemporize as occasion arises. 1879, Samuel Butler, chapter 5, in Evolution, Old & New
   The wine runs into pitchers, washing-basins, shards, chamber- vessels, and other extemporized receptacles. 1906, Thomas Hardy, The Dynasts, Part Second, Act Third
   His most famous words — "I have a dream" — were extemporized. Aug 25 2003, Emily Eakin, “How King Shaped The Dream”, in New York Times, retrieved 2011-11-08