EXTEMPORE
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”
extemporarily, extemporaneously, extempore
(adverb) without prior preparation; “he spoke extemporaneously”
Source: WordNet® 3.1
Etymology
Adjective
extempore (comparative more extempore, superlative most extempore)
Carried out with no preparation; impromptu.
Adverb
extempore (comparative more extempore, superlative most extempore)
Without preparation; extemporaneously.
Noun
extempore (plural extempores)
Something improvised.
Source: Wiktionary
Ex*tem"po*re, adv. Etym: [L. ex out + tempus, temporis, time. See
Temporal.]
Definition: Without previous study or meditation; without preparation; on
the spur of the moment; suddenly; extemporaneously; as, to write or
speak extempore. Shak.
– a.
Definition: Done or performed extempore. "Extempore dissertation." Addison.
"Extempore poetry." Dryden.
– n.
Definition: Speaking or writing done extempore. [Obs.] Bp. Fell.
Source: Webster’s Unabridged Dictionary 1913 Edition