Ailing

extemporaneous \ek-stem-puh-RAY-nee-us\, adjective:

1. Composed, performed, or uttered on the spur of the moment, or without previous study; unpremeditated; impromptu.
2. Prepared beforehand but delivered without notes or text.
3. Skilled at or given to extemporaneous speech.
4. Provided, made, or put to use as an expedient; makeshift. 

. . .the intimate goofiness of an extemporaneous story told to a child.
-- Barbara Tritel, "What the Wicked Magician Did", New York Times, February 22, 1987

She summed up the long and complex sessions in an hour's extemporaneous speech that was remarkable for its organization, pithiness and coherence.
-- "Anna Freud, Psychoanalyst, Dies in London at 86", New York Times, October 10, 1982

In fact, his particular strength may well have been improvisation, and he may not have been interested in committing the results of his extemporaneous performances to paper.
-- Christoph Wolff, Johann Sebastian Bach: The Learned Musician

Extemporaneous comes from Late Latin extemporaneus, from Latin ex tempore, "out of time," therefore "immediately, at the very time the occasion arises." It is related to temporary, "lasting for a limited time"; contemporary, "belonging to the same time" (con-, "with, together"); and tempo, "the rate or degree of movement in time."