[syn: extemporaneously, extemporarily, extempore]
The Collaborative International Dictionary of English v.0.48:
Extempore \Ex*tem"po*re\, adv. [L. ex out + tempus, temporis,
   time. See Temporal.]
   Without previous study or meditation; without preparation; on
   the spur of the moment; suddenly; extemporaneously; as, to
   write or speak extempore. --Shak. -- a. Done or performed
   extempore. "Extempore dissertation." --Addison. "Extempore
   poetry." --Dryden. -- n. Speaking or writing done extempore.
   [Obs.] --Bp. Fell.
   [1913 Webster]
WordNet (r) 3.0 (2006):
extempore
    adv 1: without prior preparation; "he spoke extemporaneously"
           [syn: extemporaneously, extemporarily, extempore]
    adj 1: 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" [syn: ad-lib,
           extemporaneous, extemporary, extempore,
           impromptu, offhand, offhanded, off-the-cuff,
           unrehearsed]