EXTEMPORANEOUS
extemporaneous, ad-lib, extemporary, extempore, impromptu, offhand, offhanded, off-the-cuff, unrehearsed
(adjective) with little or no preparation or forethought; “his ad-lib comments showed poor judgment”; “an extemporaneous piano recital”; “an extemporary lecture”; “an extempore skit”; “an impromptu speech”; “offhand excuses”; “trying to sound offhanded and reassuring”; “an off-the-cuff toast”; “a few unrehearsed comments”
Source: WordNet® 3.1
Etymology
Adjective
extemporaneous (comparative more extemporaneous, superlative most extemporaneous)
Without preparation or advanced thought; offhand.
Synonyms
• (without preparation): off-the-cuff, extemporal (archaic), improvised; see also impromptu
Source: Wiktionary
Ex*tem`po*ra"ne*ous, a. Etym: [See Extempore.]
Definition: Composed, performed, or uttered on the spur of the moment, or
without previous study; unpremeditated; off-hand; extempore;
extemporary; as, an extemporaneous address or production.
– Ex*tem`po*ra"ne*ous*ly, adv.
– Ex*tem`po*ra"ne*ous*ness,n.
Source: Webster’s Unabridged Dictionary 1913 Edition