extempore

 
Pronunciation: /ɪkˈstɛmp(ə)ri, ɛk-/

adjective & adverb

  • spoken or done without preparation: [as adjective]: extempore public speaking [as adverb]: he recited the poem extempore

Origin:

mid 16th century: from Latin ex tempore 'on the spur of the moment' (literally 'out of the time')